WWW Overview:

WWW stands for World Wide Web. A technical definition of the World Wide Web is: all the resources and users on the Internet that are using the Hypertext Transfer Protocol (HTTP).

A broader definition comes from the organization that Web inventor Tim Berners-Lee helped found, the World Wide Web Consortium (W3C). The World Wide Web is the universe of network-accessible information, an embodiment of human knowledge.

In simple terms, The World Wide Web is a way of exchanging information between computers on the Internet, tying them together into a vast collection of interactive multimedia resources. Internet and Web is not the same thing: Web uses internet to pass over the information.

Evolution:

World Wide Web was created by Timothy Berners Lee in 1989 at CERN in Geneva. World Wide Web came into existence as a proposal by him, to allow researchers to work together effectively and efficiently at CERN. Eventually it became World Wide Web. The following diagram briefly defines evolution of World Wide Web:

WWW Operation:

WWW works on client- server approach. Following steps explains how the web works:

User enters the URL (say, http://www.tutorialspoint.com) of the web page in the address bar of web browser.

Then browser requests the Domain Name Server for the IP address corresponding to www.tutorialspoint.com.

After receiving IP address, browser sends the request for web page to the web server using HTTP protocol which specifies the way the browser and web server communicates.

Then web server receives request using HTTP protocol and checks its search for the requested web page. If found it returns it back to the web browser and close the HTTP connection.

Now the web browser receives the web page, It interprets it and display the contents of web page in web browser’s window.

Internet is defined as an Information super Highway, to access information over the web. However, It can be defined in many ways as follows:

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 110.22.33.114) 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.

For example, a DNS server will resolve a name http://www.k.gacademy.com to a particular IP address to uniquely identify the computer on which this website is hosted.

Internet is accessible to every user all over the world

Evolution

The concept of Internet was originated in 1969 and has undergone several technological & Infrastructural changes as discussed below:

The origin of Internet devised from the concept of Advanced Research Project Agency Network (ARPANET).

ARPANET was developed by United States Department of Defense.

Basic purpose of ARPANET was to provide communication among the various bodies of government.

Initially, there were only four nodes, formally called Hosts.

In 1972, the ARPANET spread over the globe with 23 nodes located at different countries and thus became known as Internet.

By the time, with invention of new technologies such as TCP/IP protocols, DNS, WWW, browsers, scripting languages etc. Internet provided a medium to publish and access information over the web.