i know that there is the MIG, TIG, and the Arc welders. what are the differneces between them? i know that the TIG is tungsten or something. help a brother out and gimme some info. i was leaning towards getting a MIG self feeding welder on ebay for about $300ish. let me know if anyone has any suggestions.

china
ps: i just wanted a welder so that i can bullshit and build some cool stuff. i really want to have the ability to do my own exhausts and perhaps a roll cage (nothing too serous, just to have something to do)