On the 23rd day of the A2Z Challenge 2019, I shall talk about the A2Z of World Wide Web. When we think of WWW (World Wide Web) we often think only of the Internet. Internet and Web isn’t the same thing, the Web is just a part of the Internet. It is one of the several ways to retrieve information from the Internet. The web uses HTTP (Hypertext Transfer Protocol) to exchange data.

The World Wide Web was invented by Sir Tim Berners-Lee in 1989 at CERN (European Organization for Nuclear Research) in Geneva. Later he founded, the World Wide Web Consortium (W3C). This organisation is responsible for developing protocols and guidelines that ensure long-term growth for the Web.

A2Z of World Wide Web- Evolution of Web

The Web (Web 1.0) was first launched in 1991. With the advancement of technology, newer versions in the form of Web 2.0 and Web 3.0 came into existence.

Web 1.0

It is also called the ‘Readable’ version of the web. Webpages were simple and static – only images and hyperlinks. There was no option for user interaction.

Web 2.0

It is also called the ‘Writable’ version of the web. Pages were dynamic and enabled user interaction.

Web 3.0

It is also called the ‘Executable’ version of the web. It includes support for Artificial Intelligence and 3D graphics.

A2Z of World Wide Web- How it works?

1. A user enters the URL of a website (say, https://www.hitechup.in) in the address bar of a web browser.
2. The web browser requests the DNS (Domain Name Server) for the IP address corresponding to www.hitechup.in.
3. The DNS returns the IP address for the server that hosts www.hitechup.in (say, 168.212.226.206).
4. The browser sends the request for web page to the server that hosts the website using the IP address sent by the DNS.
5. The web server receives the request and checks for the requested web page.
   1. • If found, it returns it back to the browser.
      • Else, it returns an error message.