Extension Name of Some Files

A Website Window To Focus Upon Complete Computer Education

Windows Operating System

A Website Window To Focus Upon Complete Computer Education

Data Communication

A Website Window To Focus Upon Complete Computer Education

Some Abbreviations In Computer

A Website Window To Focus Upon Complete Computer Education

What Is The Internet

A Website Window To Focus Upon Complete Computer Education

Aug 3, 2013

LEARNING HTML

Introduction:
HTML stands for Hyper Text Markup Language. HTML used by web browsers in determining how to display a web page. it is the underlying foundation of website design. it is a combination of plain text and tags. tags tell browser how to display contents of page. you use tags every time you want to format a text, insert image or table. HTML documents are also called web pages.





Role of each tag in a document:
1. <html></html> all HTML documents begin and end with these tags. they tell browser that it is an HTML document.

2. <head></head> head tags encapsulate meta information, such as the document's title, keywords and description information that will be used by search engines.

3. <title></title> title tags defines title of the document, that will be displayed in title bar of browser.

4. <body></body> this is body section of document and document's viewable contents will be inserted here.

5. the text between <h1> and </h1> is displayed as a heading.

6. the text between <p> and </p> is displayed as a paragraph.


HTML can be edited by using a professional HTML editor like:
1. Adobe Dreamweaver.
2. Kompozer Tutorial.
3. Microsoft Expression Web.
4. CoffeeCup HTML Editor. 


1.The structure of an HTML document:


<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html>
         <head>
               <title>Example Page</title>
        </head>
        <body>
        <h1>Hello India</h1>
       </body>
      </html>

Output would be:

 

2.Change Background Color:

<html>
<head>
<title>my first web page</title>
</head>
<body bgcolor="#0099ff">

my name is Manik Sarkar

</body>
</html>

  Output would be:

         



3.Create Table:

<table border=1 bgcolor=#ccffoo>
<tr>
<td>Computer</td>
<td>Software</td>
<td>Download</td>
</tr>
</table>   

Output would be:


 

4.Create Link:

The HTML code for a link looks like this
<a href="url">Link Text</a>

Example:

<a href="http://www.computinga2z.blogspot.com/">Computer Learn</a>

Which will display like this:   Computer Learn
      

5.Add Images:

The HTML code for  images look like this
<img src="url" alt="some text">

Example:

<img src="http://hdnaturepictures.com/wp-content/uploads/2013/05/Green-Mountain-Wallpaper.jpg" alt="mountain">

Jul 30, 2013

LEARNING C PROGRAMMING

History of 'C' Programming Language:
C programming is a popular computer programming language which is widely used for system and application software. C programming language is a structure oriented programming language. C was developed at Bell Laboratories in 1972 by Dennis Ritchie. C programming features were derived from earlier language called "B"(BCPL language). C language was invented for implementing UNIX operating system. In the year 1978, Dennis Ritchie and Brian Kernighan published the first edition "The C programming language" and commonly known as K&R C. In 1983, the ANSI (American National Standards Institute) established a committee to provide a modern, comprehensive definition of C. The resulting definition, the ANSI Standard, or ANSI-C was completed late 1988. Today's most popular LINUX OS and RBDMS MySQL have been written in C.

The 'C' Compiler:
the source code written in source file is the human readable source for your program. it needs to be compiled, to run into machine language so that your CPU can actually execute the program as per instructions given. this C programming language compiler will be used to compile your source code into final executable program. there are many compilers available on the internet and sold commercially in stores or online.


Top 10 C/C++ Compilers and IDEs:
1.Eclipse 


C  Programming



Features of 'C' Language:
1. Powerful.
2. Low level features.
3. High level features.
4. Portability.
5. Bit manipulation.
6. Modular programming.
7. Reliability.
8. Flexibility.
9. Interactivity.
10. Efficiency and effectiveness.




Some Example:

Example-1

                         #include <stdio.h>
                     int main ( )
                  {
                     /*my first program in C */
                     printf ("Hello, India!  \n");

                       return 0;
                  }


Output would be-       "Hello India"


A   C program basically consists of the five parts ...
1.Preprocessor Commands:  The first line of the program  #include <stdio.h> is a preprocessor command which tells a C compiler to include stdio.h file before going to actual compilation.

2.Functions:  The next line int main ( ) is the main function where program execution begins.

3. Variables:  The next line /*........*/ will be ignored by the compiler and it has been put to add additional comments in the program. So such lines are called comments in the program.

4. Statements and Expressions:  The next line printf(.......) is another function available in C which causes the message "Hello, India!" to be displayed on the screen .

5. Comments:  You will be able to see "Hello India" printed on the screen.

Jul 26, 2013

LEARNING JAVA

Introduction:
Java is an object-oriented programming language, which can be used to do any of the thousands of things that a computer software can do. With the features it offers, java has become the language of choice for internet and intranet applications. Java plays an important role for the proper functioning of many software-based devices attached to a network. The kind of functionality the java offers, has contributed a lot towards the popularity of java.

                   Java is both, a programming language and a platform. Like any other programming language, you can use java to write and create various types of computer applications. Java is also a platform for application development. The word 'platform' generally is used to refer to some combination of hardware and system software.

Java Programs


History of Java:
In the following lines, the history of java can be found out in the java timeline.

1991: James Gosling develops Oak(later renamed java) language for programming intelligent consumer electronic devices.

1993: World Wide Web explodes.

1995: Java formally announced. Incorporated into Netscape web browser.

1996: Java development kit (JDK) 1.0 ships. java beans component architecture Corel Office for java preview. Sun announces java station network computer. Sun announces 100% pure java initiative.

1997: JDK 1.1 launched. Java servlet API released.

1998: JDK 1.2 launched. Sun introduces community source 'open' licensing. Sun produces a JDK 1.2 for Linux.

1999-2001: JDK 1.3 released. JDK's also produced by IBM on multiple platforms. Java based application servers (BEA, IBM websphere etc.) become popular. J2EE (Java 2 Enterprise Edition), J2SE(Java 2 Standard Edition), J2ME(Java 2 Micro Edition) appear.

2002: Java support for web services officially released via the java web services developer pack.

Characteristics of Java:
1.Write once run anywhere(WORA):  The java programs need to be written just once, which can be run on different platforms without making changes in the java program.

2.Light weight code:  With java, big and useful applications can also be created with very light code. No huge coding is required.

3.Security:  Java offers many security features to make its programs safe and secure.

4.Built in graphics:  Java offers many built in graphics features and routines which can be used to make java application more visual.

5.Object-oriented language:  Java is object-oriented language, thereby, very near to real world.

6.Supports multimedia:  Java is ideally suited for integration of video, audio, graphics and animation in internet environment.

7.Platform independent:  Java is essentially platform independent. Change of platform does not effect the original java program or application.

8.Open product:  Java is an open product, freely available to all. However, there exist some special time saving java development kits, which can be availed by paying small amounts.

Types of Java:
There are two types of java programs.
1.Internet Applets:  Internet applets are small programs that are embedded in web pages and are run on the viewers machine in a secured manner by java capable browsers. Applets are designed to be delivered to internet web browsers and that is why an applet has a built-in graphical window. But java applets have some security restrictions.

2.Stand Alone Applications:  These type of java program is much more interesting. It is generally a software application that does not require low level operating system or hardware access. This includes most off the usual desktop applications such as word processors or spreadsheets. Stand alone java applications could be distributed on standard ISO 9660 format CD-ROMs and installed on any java capable machine. Every stand alone application of java begins executing with a main method. 

Some Simple Java Programs:
Let us now have a look at an example java program. Following lines show a simple and short example java program - Hello World.

Example-1

                          /*program Hello World*/
                             class Hello World
                      {
                             public void say Hello( )
                              {
                                     system.out. printIn("Hello World!!");
                                 }
                           }         //class definition ends here

          Let us now examine parts of this sample program.

class Hello World
                       The line class Hello World means that a class is being defined. After the class name, the data members and member functions of the class are defined within curly braces {  } .

Method say Hello
                     The Hello World class contains one method - the Say Hello method. This is a member function of class Hello World.

System.out.printIn("Hello World!!")
                       This statement prints Hello World!! on the standard output device which is generally your monitor.

Comments /* .....*/ and // ....
                        The text enclosed within /*...... */ , called comments , is purely for enhancing readability. The comments are ignored by the compiler and not executed at all even if you write a valid Java statement within /*......*/. within /*........*/, multi-line comments can be inserted but with // .... only single line comment can be inserted.


Example-2

/* java short example 
    this java example shows how to declare and use java primitive         short variable
    inside a java class.
*/

       public class JavaShortExample {
              public static void main(String[]args) {
  
              /*
               *short is 16 bit signed type ranges from - 32,768 to 32,767.
               *
               *Declare short variable as below
               *
               *short <variable name> = <default value>;
               *
               *here assigning default value is optional.
               */

                 short s1 = 45;
                 short s2 = 35;

            system.out.printIn("value of short variable b1 is :"+s1);
            system.out.printIn("value of short variable b1 is :"+s2);
         }
 }

/*

             output would be.... 
               value of short variable b1 is :45
               value of short variable b2 is :35
*/ 
       


Jun 17, 2013

A WEB PAGE

A web page is a document, usually written in Hypertext Markup Language(HTML), which can be accessed on the internet. Web pages may contain text, pictures, movies, sounds, graphics, information and hyperlinks to other web pages and files.

                    Web page is the basic unit of information on the world wide web. It contains text and graphics and other media. Like a book or magazine's page, a web page can be of any length but results are obtained for shorter page length

                     A document created with HTML as a part of a group of hypertext documents or resources available on the world wide web, collectively is known as a website. One can read HTML documents from internet or from local hard disk drive with the help of a software called a web browser. Web browsers read HTML
A Web Page
documents and display them as formatted presentations, with any associated graphics, sound and video on a computer screen. Web pages can contain hypertext links to other places within the same document, to other documents at the same website or to documents at other websites. These also can contain fill-in forms, photos, large clickable images, sounds and videos for downloading.


                       Thus web page is a single document on the world wide web and it is specified by a unique address or URL and it may contain text, hyperlinks and graphics.

                       The web uses the metaphor 'pages', for the organization of information. One page is actually a text file marked up in HTML. It appears in web browser as a page containing images, text, hypertext and graphical links to other points on the same page, other pages, large images, sound or movies. Technically speaking, one page is one computer file that has been marked up with HTML codes. To a person using the web, a page is that unit that can be scrolled through using web browser's scrolling tools. A web page has a top and a bottom, a beginning and an end.

                       Web page is simply collection of electronic information on the web, formatted in HTML and addressed by a single URL.

                       The semantic web provides a common framework. It allows data to be shared and reused by application, enterprise and community boundaries. It is based on the resource description framework, which integrates a variety of applications using XML for syntax and URLs for naming.

                      The semantic web is an extension of the current web in which information is given well-defined meaning, better enabling computers and people to work in co-operation.

HTML(Hyper Text Markup Language):
Hyper text markup language(HTML) is suitable for converting ordinary text into hypertext. It is a set of special codes included to control the layout and appearance of the text. Technically, HTML is not a programming language. It combines instructions within data to form a display program, called browser. HTML has the following features ............

1. HTML is the character based method for describing and expressing the content. the content is pictures, text, sound and video clips.
2. It delivers the contents to multiple platforms.
3. It links document components or documents together to compose compound documents.
4. HTML is a type of code. It embeds simple codes within standard ASCII text documents to provide an integrated, two-dimensional display of text and graphics.
5. Any document created with any word processor and stored in ASCII format can become a web page with the addition of a few HTML codes.

                             Tim Berners Lee developed HTML in early 1990 at CERN(Conseil European De La Recherche Nucleaire), the European  Particle Physics Laboratory in Geneva, Switzerland. HTML is a public domain and not owned by anybody. The WBC(world wide web consortium www.w3.org) is the body, which controls the HTML standards. To develop web pages, we always remember the following three C's of web page design.....

1. Quality content.
2. Artistic composition.
3. Reader convenience.

                           All web pages should be written, viewed and tested before installing the same on a public web server. Any web page on a web server requires ongoing maintenance. Timely information on developed pages should continue to be updated. External hyperlinks should be periodically tested to ensure that these are not obsolete.

                           Web page design is not like desktop publishing where the author has absolute control over the final presentation of the text. Web page display is always dependent on input from both the web page author and the web page reader. Control on the part of the reader is essential because any given browser may be operating on any number of hardware platforms. Large complicated screen displays may be unreadable on the small screen of a laptop computer. For example, a paragraph indentation of 10 characters looks fine in a window that displays 100 characters per line, but it is not so fine in a window that displays only 30 characters per line. Also, browsers wrap text from one line to the next, unless instructed otherwise. Since users can re-size their browser's display window, one user may see the text wrapped after 80 characters, while another sees it wrapped after 60. Users have no control over these things and they may only hope to create a web page that will be easy to read for a majority of users. This makes text formatting in HTML inherently more limited than text formatting with a word processor. It is difficult to know the dimensions of the window prior to displaying it on screen. These uncontrollable factors make to format a challenge to format HTML text. There are also web page construction kits and these can be used to build prefabricated web pages from HTML template. Each template is designed for a particular genre(Example- a personal home page or a small business advertisement). For this, it is required to select a template and add the content.

                           Special HTML editors, interactive assistants and construction bits are all instructional for beginners. The most advanced HTML features are associated with graphics and special effects.


A SAMPLE WEB PAGE:
A web page is just a text file. However, it is a text file that contains HTML tags in addition to the text that appears when the page is viewed with a web browser. We can start a web page by writing all of the visible text first and then inserting the HTML tags later. We can edit web page using any text editor or word processor as long as the file is saved as plain ASCII text. A well designed web page normally consists of three parts..........
1. Head
2. Body
2. Graphics

                         The head is reserved for the title of the document as well as some optional data. Every web page should have title which will be displayed in the title bar of a web browser. The title is also important to some search engines which may weigh keywords found in a title more heavily than other keywords. A web page is built with HTML elements, and each element is associated with an HTML tag or pair of tags. For example, the title of a web page is an HTML element, and it is created with a pair of tags that mark the beginning of the title and the end of the title -<title>and</title>:


STANDARD GENERALIZED MARKUP LANGUAGE(SGML):
HTML is a subset of SGML. SGML organized in 1960s at IBM to overcome the problems in moving the documents across the multiple hardware platforms and operating systems. IBMs efforts were called GML(general markup language). Later in 1980, SGML came into existence.

                               


                      

May 21, 2013

HACKING AND PIRACY

Hacking refers to attempts to gain information from otherwise undisclosed areas.


                   Hacking is the most commonly known computer crime, however people refer to hacking as committing any criminal act using a computer while this is not the case. Hacking is similar to breaking and entering however instead of breaking into a house you break some ones computer security and entering is similar to accessing someone's computer files, once in, they steel you files and use them for personal befit. While it is not a prerequisite most hackers are also virus creators. There are two types of hackers
Hacking and Piracy
black hat hackers and white hat hackers, black hat hackers are the ones who are there for malicious purposes such as steeling, storing or vandalising data. While white hat hackers are legally intrudes who are hired by administrators to test there system for security flaws. There are also many other variants such as gray hat hackers which is between black hat and white hat hackers.

                      Piracy refers to the unauthorized duplication of computer software. 

SOFTWARE PIRACY:  
As mentioned, software piracy is the unauthorized duplication of computer software. Although most computer users today are aware than unauthorized use and duplication of software is illegal, yet general disregard is shown towards treating software as valuable intellectual property. Common forms of software piracy are..........

1.Softlifting:  It refers to purchasing a single licensed copy of software and loading it onto several computers contrary to the license terms.
Example- Sharing licensed software with friends, Co-workers and others.

2.Uploading and downloading:  It refers to making unauthorized copies of copyrighted software available to end users connected to a network.

3.Software counterfeiting:  It refers to illegally duplicating and selling copyrighted software in a form designed to make it appear legitimate.

4.Hard disk loading:  It refers to installing unauthorized copies of software onto the hard disks of personal computers, often as an incentive for the end user to buy the hardware from that particular hardware dealer.

5.Renting:  It is the unauthorized selling of software for temporary use, like renting a video.

                       Software piracy means denial of intellectual property rights to the software creator or developer. It is not ethical to use someone else's property without his/her content and without giving him/her the benefit of it. Developing a software application involves a major investment of time, money and effort. Software piracy denies the creator the revenue he/she deserves and harms paying customers, who ultimately bear the cost of illegal use of products. Piracy limits the creators ability to be competitive, leading to higher-priced, less advanced products for customers.

                          Software piracy can be controlled though copyrights, patents and trademarks. A copyright is the exclusive property right of the owner, creator, developer, author of a work, granted by law. It gives the owner an exclusive right to protect his work in all forms. A patent refers to special power of monopoly granted by law. Without obtaining a licence from the patent holder, the work can not be used or reproduced. And a trademark refers to the registered word, text, logo depicting the identify of a product, work or a company.

GETTING PROTECTED:
Before you implement protection measures for your computers, you must be aware of the forms of attacks that hackers may launch. In the following steps, we are going to discuss different forms of attacks that generally take place.

1.Spamming:  Spamming refers to the sending of bulk-mail by an identified or unidentified source. In non-malicious form, bulk advertising mail is sent to many accounts. In malicious form(e-mail bombing), the attacker keeps on sending bulk mail until the mail server runs out of disk space.

2.Computer viruses:  Computer viruses are malicious codes/programs that cause damage to data and files on a systems. Viruses can attack any part of a computer's software such as boot block, operating system, system areas, files and application-program-macros. 

3.Worms:  A worm is a self-replicating program which eats up the entire disk space or memory. A worm keeps on creating its copies until all the disk space or memory is filled.

4.Trojan horses:  A Trojan horse is a program that appears harmless(such as a text editor or a utility program) but actually performs malicious functions such as deleting or damaging files.

5.Sweeper:  This is another malicious program used by hackers. It sweeps or deletes all the data from the system.

6.Denial of services:   This type of attack eats up all the resources of a system and the system or applications come to a half. Example of such an attack is flooding a system with junk mail.

7.Password guessing:  Most hackers crack or guess passwords of system accounts and gain entry into remote computer systems. And then they use it for causing damages in one or another form.

                          There are other forms of attacks also such a sniffing, packet forge spoofing, IP spoofing etc. But we are not discussing them as in order to understand these, one needs to know the working of networks.


PROTECTIVE MEASURES:
Now after knowing different forms of attacks, let us now discuss different protective measures that may be taken against such attacks.

                              The entire computer security is based on a system of safeguards that are designed to protect a computer system from deliberate or accidental access and/or damage by unauthorized persons.

                               The combination of identification, authentication and authorization can control access to a system. This combination is very useful especially in network security. Various techniques used for network security are .......

1.Authorization:  Authorization is performed by asking the user a legal log in id. If the user is able to provide a legal log in id, he/she is considered an authorized user.

2.Authentication:  Authentication is also termed as password protection as the authorized user is asked to provide a valid password and if he/she is able to do this, he/she is considered to be an authentic user.

3.Firewall:  A system designed to prevent unauthorized access to or from a private network is called Firewall. Firewalls are a mechanism to prevent unauthorized internet users from accessing private networks connected to the internet, especially intranets.

Securing Data:
Though controlled access to a system indirectly secures data, yet there are some other measures that must be taken in case data gets corrupted even after taking security measures. These include taking backups from time to time, preparing recovery mechanism, maintaining transaction logs and having a proper disaster recovery plan. Data security also involves measures like secured waste, effective passwords, internal controls, conducting audits, and using cryptography.


COMPUTER CRIME:
Computer crime or the electronic crime may include thefts or actions in electronic form that causes damage or difficulty to other computer users. Computer crime may be of following types ......


  • Theft of computer time.
  • Theft, destruction or alteration of data.
  • Theft, destruction or manipulation of programs.
  • Hacking.                                 



             some white-collar crimes are .......

  • Theft of data or software.
  • Theft of documentation.
  • Sabotage.
  • Illegal modification of data.
  • Forging or falsification of data.
  • Embezzling funds.
  • Fraud in figures.
  • Installing 'Bugs'.
  • Selling reports, paper output.


                        Reasons for computer crimes
Computer crimes take place more often because of nearly no detection and prosecution. Major reasons for computer crimes taking place are .....
  • Little understood by police, courts.
  • Low detection rate, often accidental.
  • 3-defined laws.
  • Data 'value' hard to define.
Clearly defined laws and strict implementation of these laws can reduce computer crimes to a great extent.


May 5, 2013

SEARCH ENGINES

Definition :
A search engine is a program that searches through a database of web pages for particular information.


                            Until now, you were surfing internet by visiting sites known to you. What if you want to view particular information, but you do not know which site would provide you that information. In that case, you need to search for that information on the web. And this can be done through search engines, a program used for searching information on the internet.

SOME POPULAR SEARCH ENGINES :
www.Google.com
www.Bing.com
www.Yahoo.com
www.Ask.com
www.Duckduckgo.com
www.Dogpile.com
www.Blekko.com
www.Aol.com
www.Webopedia.com
www.Altavista.com
www.Teoma.com
www.Entireweb.com


Search Engines

FINDING INFORMATION USING A SEARCH ENGINE :
There are many search engines on the web.The searching process is similar on these search engines. To search for web pages pertaining to a specific information, all you have to do is .............

1. Go to the home page of the search engine.
2. Type the information to be searched for in the box provided for it.
3. Now click at Search button next to it. Within a few seconds, the search engine will search for that information and display the links to the web pages, which are linked to your desired information in some way.

HOW SEARCH ENGINE WORKS :
In a search engine, you can type keywords to search for and a search engine searches them, on the web and provides you the details. A search engine works with the help of following three elements.

1. Spiders or Webcrawler or Bots or Agents : The search engines use a software called spider or webcrawler or Robot or bot or Agent which comb the internet looking for documents and their web addresses. The spiders or webcrawlers perform the methodical searches needed to find information.

                         The bots or spiders are given direction by the search engine and they crawl from one server to another, compiling the huge lists of URLs (based upon the directions) given by search engine.

2.Indexing Software and Database : The lists of documents and web addresses collected by bots are sent to the indexing software. The indexing software extracts information from the documents and web addresses, prepares on index of it and stores in a database.

                          The kind of information indexed depends upon the particular search engine. Some index every word in the document, others index the document title only.

3.Search Algorithm : When you perform a search by entering keywords, the search engine software searches its database (in which indexing software stores its entries) using a particular search method called Search Algorithm. And then it displays the matching documents or web addresses.

SOME SEARCHING TIPS :
To effectively search for desired information, you must learn the art of framing search queries. in the following lines, we are going to discuss some tips for the same..............

1. Do not ask questions. For example, if you want to find out some information about home minister of India and if you type in the search box, then you may end up getting lakhs of matches but most being useless.
                          
                              This is because the search engine searches for each word in the search query separately. That is, in this case, your search will search for words "who", "home", "minister", "India" separately and then display all the results. Common words like "a", "and", "is", "the" etc. are dropped.

2. Surround your query in quotes or put some punctuation marks (, . ; - ) if you want it to be treated as single phrase rather than a series of individual search terms. For example, if you want to search for the book titled God of Small Things then you may write it as
                       "god of small things"
   or as              god-of-small-things
   or as              god ; of ; small ; things

3. Use wildcard * for pattern matching. For instance, if you want to search for certain things starting with dir, then you may write

                 dir*

In the search box and your search engine will search for many words starting with dir . Example: dire, direct, direction, directive, director etc.

4. The lowercase word matches are not case-sensitive but uppercase words are case-sensitive for example, if you write

                           program

It will match with program or programs or PRogram ....... and PROGRAM .

But if you write

      PROgram

Then it will match PROgram only.

5. To specify that a word or phrase must appear in matched documents, put a plus sign (+) immediately before it. For example, the following query

+boston +university

Will match with web pages having both the words boston and university.

6. To specify that a word or phrase must not appear in matched documents, put a minus sign (-) immediately before it.

Example:
                    +asia-china


Apr 22, 2013

WINDOWS OPERATING SYSTEM

To avoid the drawbacks in using DOS, the operating system windows are preferred to DOS as these are highly graphical in nature and interacts with the user using pictorial forms. Hence,
windows are of graphical user interface(GUI) types. The use of a mouse is imperative in the windows environment.
    
                 The first version of windows version 1 was basically and initially developed by Microsoft Corporation in USA in 1985 as a complement of DOS to avoid the limitations. This version is not accepted by computer world due to some limitations. The next versions are 1.2, 2.1 and 3.0 . However, the first successful version of windows is windows 3.1 and it was released in 1992.

                The version windows 3.1 did not gain much popularity. The computer users accepted the windows in late eighties when the windows 3.1 was updated into the work group  version windows 3.11 . both the windows 3.1 and 3.11 are not actually of full-fledged operating system. In fact during operations, DOS works at the background and the windows act as an interface system between operating system and user. In 1995, Microsoft Corporation
Windows Operating System
launched windows 95 which is a full-fledged operating system and any PC range computer can directly run using windows 95. The new versions of windows are windows 97 and windows 98 etc. Are more powerful and rich with the built-in facilities and becoming more and more popular. The updated and networked version of windows are windows XP, windows 7, windows 8 etc. These are very popular and presently used in all PC range computers.

WINDOWS FEATURES:
Graphical User Interface(GUI):  In windows environment, writing commands are not required. It can be done by clicking the icons from a group of small pictures. In this case, it is not required to remember all the commands along with all the options and syntax.

Similar Set Of Commands:  The softwares used in windows environment use similar set of commands. Hence, it is not required to remember the commands for all the softwares.

Multitasking Facility: In windows environment, a number of tasks can be performed by partitioning the screen into a number of segments in which each window can perform individual task.

Dynamic Data Exchange: The windows provides facility to share and exchange data from any software very easily.

Object Linking And Embedding: Windows provides facility of clipboard and using this any object can be selected from any window based application and embed the part to any other application. Also the linking can be done between two objects. Here any change to any object automatically changes the linked object.

Open Database Connectivity: Here, data-based applications are designed to that database created by any application. This can be used and updated by any other application. Using this facility, programmers can develop more robust and versatile programs or packages.

Multi User Operating System: In developed version of windows, a number of users can operate simultaneously with one computer from different terminals.

Easy User Interface: In windows environment, two systems, though not compatible, can work together very efficiently.

Better Resource Management: The resource management can be done more efficiently.

Better Utilities And Accessories: Windows provides a good number of utilities and accessory programs and these are extremely helpful.

Plug And Play: This facility needs no installation or other formalities during addition or alteration of attached devices like CD drive, sound systems, video systems etc.

Online Help: Windows provides a powerful online help facility and using these, users can get valuable help and instructions during working.

FEATURES OF SOME WINDOWS OPERATING SYSTEMS

WINDOWS XP(October 2001)
a. Released in 2001.
b. Offers some brighter color choices.
c. Variants-XP professional, XP home, windows XP media center edition and XP embedded also created 64 bit windows XP for use with AMD's opteron and Athlon 64 CPUs.
d. XP has digital media support. Through the use of windows media player, users of XP can take advantage of digital broadcast support as well as video and audio rendering for multimedia projects.
e. Advanced networking and communication -- XP takes advantage of universal plug and play support, which enables PC to find and use hardware connected via a network without forcing the user to configure the system or install drivers. It also makes use of internet connection sharing, which allows users to connect multiple computers to the internet via a single connection.
f. Advanced mobile computing-- through the use of features like automatic configuration, one can connect an XP based laptop to a desktop PC without knowing different types of network settings. Cellular phone can be used to connect to network.

WINDOWS VISTA(November 2006) 
a. Offered an advancement in reliability, security, ease of deployment, performance and manageability over Windows XP.
b. New in this version was capabilities to detect hardware problems before they occur, security features to protect against the latest generation of threats, faster start-up time and low power consumption of the new sleep state.
c. In many cases, Windows Vista is noticeably more responsive than Windows XP on identical hardware.
d. Windows Vista simplifies and centralizes desktop configuration management, reducing the cost of keeping systems updated.

WINDOWS 7(October 2009)
a. Windows 7 made its official debut to the public on October 22, 2009 as the latest in the 25 year old line of Microsoft Windows Operating systems and as the successor to Windows Vista.
b. Windows 7 was released in conjunction with Windows server 2008 R2, Windows 7's server counterpart.
c. Enhancements and new features in Windows 7 include multi-touch support, internet explorer 8, improved performance and start-up time, Aero Snap, Aero Shake, support for virtual hard disks, a new and improved Windows media center and improved security. 
  

Apr 18, 2013

COUNTRY DOMAIN NAMES

At the present time there are over 200 recognized country domain names.Two letter abbreviations that represent the country names are used in addresses seen on the internet.
              This list should be useful when checking the origin of your own mail.

DOMAIN NAMES      COUNTRIES 
 .af --------------------   Afghanistan
 .al --------------------   Albania
 .dz -------------------    Algeria
 .as -------------------    American Samoa
 .ao ------------------     Angola
 .ad ------------------     Andorra
 .ai -------------------    Anguilla
 .aq ------------------     Antarctica
 .ag ------------------     Antigua and Barbuda
 .ar ------------------      Argentina
 .am -----------------     Armenia
 .aw -----------------     Aruba
 .ac ------------------     Ascension Island
 .au ------------------     Australia
 .at -------------------    Austria
 .az -------------------   Azerbaijan
 .bh ------------------    Bahrain
 .bd ------------------    Bangladesh
 .bb ------------------    Barbados
 .by ------------------    Belarus
 .be ------------------    Belgium
 .bz ------------------    Belize
 .bj -------------------    Benin
 .bm ------------------    Bermuda
Country Domain Names

 .bt -------------------    Bhutan
 .bo -------------------   Bolivia
 .ba -------------------   Bosnia
 .bw ------------------   Botswana
 .bv -------------------  Bouvet Island
 .br -------------------   Brazil
 .io -------------------   British Indian Ocean Territory
 .bn ------------------   Brunei
 .bg ------------------   Bulgaria
 .bf ------------------    Burkina faso
 .bi ------------------    Burundi
 .kh -----------------    Cambodia
 .cm ----------------    Cameroon
 .ca -----------------    Canada
 .cv -----------------    Cape Verde
 .cf -----------------    Central African Republic
 .td -----------------    Chad
 .gg -----------------    Channel Islands, Guernsey
 .je -----------------     Channel Islands, Jersey
 .cl -----------------     Chile
 .cn ----------------     China
 .cx ----------------     Christmas Island
 .cc ----------------     Cocos Islands
 .co ----------------     Colombia 
 .km ---------------     Comoros
 .cg ----------------     Congo
 .ck ----------------     Cook Islands
 .cr ----------------      Costa Rica
 .ci -----------------     Cote D'ivoire
 .hr -----------------     Croatia
 .cu -----------------     Cuba
 .cy -----------------     Cyprus
 .cz -----------------     Czech Republic
 .dk -----------------     Denmark
 .dj ------------------     Djibouti
 .dm ----------------     Dominica
 .do -----------------    Dominican Republic
 .tp -----------------     East Timor
 .ec ----------------      Ecuador
 .eg ----------------      Egypt
 .sv ----------------      El Salvador
 .gq ----------------     Equatorial Guinea
 .er ----------------      Eritrea
 .ee ----------------     Estonia
 .et ----------------     Ethiopia
 .fk ----------------     Falkland Islands
 .fo ----------------     Faroe Islands
 .fj -----------------     Fiji
 .fi -----------------     Finland
 .fr -----------------    France
 .gf ----------------     French Guiana
 .pf ----------------     French Polynesia
 .tf -----------------    French Southern Territories
 .fx ----------------     French Metropolitan
 .ga ----------------     Gabon
 .gm ---------------     Gambia
 .ge ----------------    Georgia
 .de ----------------    Germany
 .gh ----------------    Ghana
 .gi -----------------   Gibraltar
 .gr ----------------    Greece
 .gl ----------------    Greenland
 .gd ---------------    Grenada
 .gp ---------------    Guadeloupe
 .gu ---------------    Guam
 .gt ----------------    Guatemala
 .gn ---------------    Guinea
 .gw ---------------   Guinea Bissau
 .gy ----------------   Guyana
 .ht ----------------    Haiti
 .hm ---------------   Heard and Mcdonald Islands
 .hn ----------------   Honduras
 .hk ----------------   Hong Kong
 .hu ----------------   Hungary
 .is -----------------   Iceland
 .in ----------------    India
 .id ----------------    Indonesia
 .ir ----------------     Iran
 .iq ---------------     Iraq
 .ie ---------------     Ireland
 .im ---------------    Isle of Man
 .il -----------------   Israel
 .it -----------------   Italy
 .jm ---------------    Jamaica
 .jp ----------------   Japan
 .jo ----------------   Jordan
 .kz ----------------  Kazakhstan
 .ke ----------------  Kenya
 .ki -----------------  Kiribati
 .kp ----------------  Korea, Democratic People's Republic Of
 .kr ----------------   Korea, Republic Of
 .kw ---------------   Kuwait
 .kg ----------------   Kyrgyzstan
 .la -----------------   Laos
 .lv -----------------   Latvia
 .lb -----------------   Lebanon
 .ls -----------------    Lesotho
 .lr -----------------    Liberia
 .ly -----------------   Libyan Arab Jamahiriya
 .li ------------------  Liechtenstein
 .lt ------------------  Lithuania
 .lu -----------------  Luxembourg
 .mo ---------------   Macao
 .mk ---------------   Macedonia
 .mg ---------------   Madagascar
 .mw --------------   Malawi
 .my ---------------   Malaysia
 .mv ---------------   Maldives
 .ml ----------------   Mali
 .mt ----------------  Malta
 .mh ---------------  Marshall Islands
 .mq ---------------  Martinique
 .mr ---------------  Mauritania
 .mu --------------- Mauritius
 .yt ----------------  Mayotte
 .mx --------------   Mexico
 .fm ---------------  Micronesia
 .md --------------- Moldova
 .mc --------------- Monaco
 .mn --------------- Mongolia
 .ms ---------------  Montserrat
 .ma --------------   Morocco
 .mz --------------   Mozambique
 .mm -------------   Myanmar
 .na ---------------  Namibia
 .nr ---------------   Nauru
 .np ---------------  Nepal
 .nl ----------------  Netherlands
 .an ---------------  Netherlands Antilles
 .nc ---------------  New Caledonia
 .nz ---------------  New Zealand
 .ni ---------------   Nicaragua
 .ne --------------   Niger
 .ng --------------   Nigeria
 .nu --------------   Niue
 .nf ---------------  Norfolk Island
 .mp --------------  Northern Mariana Islands
 .no ---------------  Norway
 .om --------------  Oman
 .pk ---------------  Pakistan
 .pw --------------   Palau
 .pa --------------- Panama
 .pg --------------- Papua New Guinea
 .py --------------- Paraguay
 .pe --------------- Peru
 .ph --------------- Philippines
 .pn --------------- Pitcairn
 .pl ---------------  Poland
 .pt ---------------  Portugal
 .pr ---------------  Puerto Rico
 .qa --------------   Qatar
 .re --------------    Reunion
 .ro --------------   Romania
 .ru --------------   Russia
 .rw -------------   Rwanda
 .kn -------------   Saint Kitts and Nevis
 .lc --------------   Saint Lucia
 .vc -------------   Saint Vincent and The Grenadines
 .ws -------------  Samoa
 .sm -------------  San Marino
 .st --------------  Sao Tome and Principe
 .sa -------------   Saudi Arabia
 .sn -------------  Senegal
 .sc --------------  Seychelles
 .sl --------------- Sierra Leone
 .sg -------------- Singapore
 .sk -------------  Slovakia
 .si -------------- Slovenia
 .sb ------------- Solomon Islands
 .so ------------- Somalia
 .za ------------- South Africa
 .es ------------- Spain
 .lk ------------- Sri Lanka
 .sh ------------- St. Helena
 .pm ------------ St. Pierre and Miquelon
 .sd ------------- Sudan
 .sr -------------  Suriname
 .sj -------------  Svalbard and Jan Mayen Islands
 .sz ------------   Swaziland
 .se ------------  Sweden
 .ch -----------   Switzerland
 .sy ------------  Syria
 .tw ------------  Taiwan
 .tj -------------  Tajikistan
 .tz ------------   Tanzania
 .th ------------   Thailand
 .bs ------------   The Bahamas
 .ky ------------  The Cayman Islands
 .tg -------------  Togo
 .tk -------------  Tokelau
 .to -------------  Tonga
 .tt --------------  Trinidad and Tobago
 .tn -------------  Tunisia
 .tr -------------   Turkey
 .tm ------------   Turkmenistan
 .tc -------------   Turks and Caicos Islands
 .tv -------------   Tuvalu
 .ug ------------   Uganda
 .ua ------------   Ukraine
 .ae ------------   United Arab Emirates
 .uk ------------   United Kingdom
 .us -------------  United States
 .um ------------  United States Minor Outlying Islands
 .uy -------------  Uruguay
 .uz -------------  Uzbekistan
 .vu -------------  Vanuatu
 .va -------------  Vatican City State 
 .ve -------------  Venezuela
 .vn -------------  Vietnam
 .vg -------------   Virgin Islands(British)
 .vi --------------  Virgin Islands(US)
 .wf -------------   Wallis and Futuna Islands
 .eh -------------    Western Sahara
 .ye -------------    Yemen
 .yu -------------    Yugoslavia
 .zm -------------    Zambia
 .zw -------------    Zimbabwe


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