if the pages you want to run are just static ones (no queries, no form submitting, ...) you can just save them as HTML pages and open them on your pc. But if you want to manage a dynamic website (with dynamic operation : form submitting, posts, data queries) and you want to run these dynamic operations then you'll need a WebServer running on you local machine, and probably a database Server also, and the webpages are written in dynamic programming languages (php, jsp, asp, ...)