Web Browser

What is a Web Browser?

A web browser is an application for accessing websites and displaying their webpages. The most popular web browsers nowadays are¹ Google's Chrome, Apple's Safari, Microsoft's Edge, Opera, and Mozilla's Firefox. Web browsers exist in both in desktop PC's as well as smartphones and other mobile devices

They aren't to be confused with file browsers, which exist to browse your the files inside your computer. In particular, Windows used to ship with a web browser called Internet Explorer, and with a file browser called just Explorer. When someone says "browser," they normally mean a web browser, not a file one.

Originally, web browsers were only capable of displaying text and clickable links that let you navigate from one webpage to another (hence making a web of links). These web pages were written in a code language called HTML. With time, HTML pages and the browsers created to display them evolved and gained more and more features, like displaying images, playing audio, and now they even support video.

Nevertheless, fundamentally a web browser is made to display a HTML file. When you access a webpage on some URL, the web browser downloads a HTML file from that URL and then displays it. This HTML file may require several other files to be downloaded, such as images, CSS stylesheet files, and Javascript files. The browser downloads all of them at once in order to display just one single web page. Consequently, it's not unusual for a single webpage to require several megabytes to be downloaded in order to be displayed.