A web browser is a program which is used to visit web pages. The two most well-known web browsers are Netscape Navigator and Microsoft Internet Explorer,

which are used by the vast majority. Other browsers are available as well.

The very first web browser was written by Tim Berners-Lee, while at CERN (a European center for physics research). The first web browser to capture the public's

imagination was Mosaic, which was written by Marc Andreessen and other undergraduate students at the National Center for Supercomputing Applications

(NCSA) in the United States. Most of that group went on to form the core of Netscape Communications Corporation.

 A web browser works by using a special protocol called HTTP to request a specially encoded text document from a web server.

The text document contains special instructions (written in HTML) that tell the browser how to display the document on the user's screen.

The instructions may include references (hyper-links) to other web pages, text color and position, locations for various images contained in the document and where

to position them. Some web pages may use layout instructions contained in seperate documents called stylesheets.