+1.. google...
1. ask unsa manufacturer nga iya gusto, then visit manufacturer's website, from there i categorize mna nila unsay socket type and what procs thats compatible with it. they will also tell you what S bridge and N bridge chipset, what VC they support(its either NVidia/ATI) and rest of the features.
2. go to nvidia/ati website
nvidia: 2 series ang sikat run, 9 series and 200 series. example, gefore 9600GT, 9800GT. naa sad gefore GTX280, GTX285, GTX295. GTX is better than GT, the higher the number the better. 200 seriers is better than 9 series.
att: HDxxxx, like, HD4770, HD4650 = The first number is the generation, the second number is the area of capability (x4xx, x6xx, x7xx, x8xx etc), and the third number, xx5x or xx7x is the upper or lower version of that card at that level(reference:
ATI naming conventions - Graphics cards - Monitors/video) => parihas ra sad the higher the number the better
sakto c fern, it's like you're asking the meaning of life, aq p lng gani answer nimo wala pa n kaabot sa basic understanding, wa p gani q kabalo 100% correct ba gyud n.
you can always trust your all-time friend "GOOGLE".