Evolution of Networking
Computers became able to exchange data in automatic mode, which, essentially, is the basic mechanism of any computer network. Developers of the first networks implemented services for file exchange, database synchronization, e-mail and other network services.
ARPANET was established by the Advanced Research Projects Agency (ARPA) in 1969 for two main reasons:
• To allow the transfer of data between various institutes of research.
• To answer the call of the U.S. Department of Defence for a technology to provide messaging capabilities to the government in the event of nuclear war.
The World-Wide Web is a collection of documents and services. It is distributed across the Internet and linked together by hypertext links. The web is therefore a subset of the Internet.
World Wide Web was created by Timothy Berners Lee in 1989 at CERN in Geneva.
Web page is a document available on World Wide Web. A web page can contain information including text, graphics, audio, video and hyper links. These hyper links are the link to other web pages.
Web Browser is an application software that allows us to view and explore information on the web.
Following are the most common web browser available today:
WWW works on client- server approach. Following steps explains how the web works:
1. User enters the URL (say http://www. tngovernmentjobs.in/) of the web page in the address bar of web browser.
2. Then browser requests the Domain Name Server for the IP address corresponding to www.tngovernmentjobs.in.
3. After receiving IP address, browser sends the request to web page and web server using HTTP protocol.
4. Then web server receives request using HTTP protocol and checks for the requested web page. If found it returns it back to the web browser and close the HTTP connection.
5. Now the web browser receives the web page, it interprets and displays the contents of web page in web browser’s window.
Web server is a computer where the web content is stored. Basically web server is used to host the web sites.
• Internet is a world-wide global system of interconnected computer networks.
• Internet uses the standard Internet Protocol (TCP/IP).
• Every computer in internet is identified by a unique IP address.
• IP Address is a unique set of numbers (such as 126.96.36.199) which identifies a computer location.
• A special computer DNS (Domain Name Server) is used to give name to the IP Address so that user can locate a computer by a name.
• Internet is accessible to every user all over the world.
• The origin of Internet is devised from the concept of Advanced Research Project
Agency Network (ARPANET).
• Internet allows us to communicate with the people sitting at remote locations. There are various apps available on the web that uses Internet as a medium for communication. One can find various social networking sites such as:
• One can surf for any kind of information over the internet with the help of a search engine.
• Apart from communication and source of information, internet also serves a medium for entertainment. Following are the various modes for entertainment over internet.
o Online Television
o Online Games
o Social Networking Apps
• Internet allows us to use many services like:
o Internet Banking
o Online Educational Services
o Online Shopping
o Online Ticket Booking
o Online Bill Payment
o Data Sharing
• Internet provides concept of electronic commerce, that allows the business deals to be conducted on electronic systems
Topology describes the physical cabling layout and the logical way of moving data between components.