Think of tags as commands . For example if you want a line of text to be bold. There you have an example of how tags make commands and tell the browser how to display the text. Just like telling a dog to sit. You give the command.
Different tags call different functions.
A full list of html tags and their functions is provided here. Like to write a page of html. C'mon, let's do it together here . SwapaPage Click here Swap an entire page. Your page will be shown by other web sites.