There is a thread already running - First of all you need to tell us what is your operating system eg Are you on Windows or Mac, and also; what versions are you running? With that I'm sure many AB's will be able to give you an opinion.
Hi psybbo ... Go into your search engine main page; and type in "Google Chrome v's Firefox" - should be an opportunity for you to compare the features that you're looking for. Then decide to download the one you fancy from the download box indicated. You could download both and see which one really suits you. Happy Browsing!
You don't "change" your browser as you can have as many different browsers installed that you want.
But you just use the one you want, or you can use each for different things if you want.
So if you had IE and Chrome and Firefox installed you can use just one of them, or IE for some web sites, Chrome for others, Firefox for others, its all up to you.