Okay, so here's the thing. IE is a standard browser that comes with all Microsoft products. Thus, it has to be made easier so all the n00bs can use it without many difficulties. The thing is, this over simplification leads to slower browsing, no add-ons, and limited HTML/CSS viewing.
Firefox comes with add-ons, which are amazing, it can browse alot faster, if you have a decent processor and RAM, and it can view alot more of the CSS codes than IE can.
If you dont know what CSS stands for, it means: Cascading Style Sheet. CSS, javascript, are what give all web pages their glossy, beautiful look, when used properly.
I'm a Web Site Developer, so take it from me, Firefox is ALOT better than IE
*PS: never used Chrome, my computar is too slow for it, so give it a try to. I have heard from friends that it is really good.