Web-browsers are software-engines that are an interface between users and the complex infrastructure of the World Wide Web.

Browsers perform several functions, they read source code written by web or mobile developers and converts it into machine readable code. They are a store of data - this is where cookies, which are packets of data - live. They run network calls in the network layer of the internet to a host of servers and receive this information to transmit back to users.

In this section we look at the complex series of tasks web-browsers perform. Mobile browsers work very differently, while there are similarities, this section does not cover the differences or similarities to mobile browser architecture.