The role of a Browser

The role of a browser

We use a browser to seek information on the worldwide web. We type in characters and press enter and associated byte pulses pass in a wired or wireless fashion to a router come modem device on our Local Area Network (LAN). It knows the IP address (32 bits = 4 bytes) of our Internet Service Provider (ISP) and passes to them the digital request. If it does not know where the information is the ISP server will ask other directories on the www to search for and provide details.

Our ISP assembles a list of suitable IP addresses that might satisfy our request. They are routed with headline detail to our modem’s IP address on this wide area network (WAN). Our router despatches to the requesting IP address on the LAN the information sent over the WAN. We select an option and establish a connection, via our router come modem and ISP server, to the source IP address. Bytes of data again flow to our machine’s browser software, bringing to us the information we desire.

Our browser has been programmed to parse and make sense of the bytes of data received. It assembles the bytes as an html file and reads any bytes from javascript and css files referenced therein. The css file plays a huge part in the layout of the display whilst the javascript file can change both the content of the html files and css files.

The browser creates a Document Object Model (DOM) and a cascading style sheet model (CSSOM) and uses them to produce a render tree after which much mathematics is used to render the final layout we see on the screen.

A programmer can write html, javascript and css files and make modifications to the dom that will be meaningful and stored as bytes of data, but only if the files language syntax is adhered to.