yes indeed Ashton is correct,
OS = Operating System
Ashton is also correct about the other stuff he posted, but, make sure you physically check (don't believe the salesman) the PC you buy or build (building is a much better option, because, then you can put exactly what you want in the system) that the system you get doesn't use a crappy integreated / onboard graphics card
BTW: all at HWF are always here to help (me included)
if you have any questions, just ask, personally, i wasn't born knowing about computers, i had to learn, and i'm also always learning, so, don't feel bad if your a noob, we all were noobs, i did think i knew a lot about computers when i was employed to fix them, but, soon after i came to HWFs i realised i knew :swear: all, never be ashamed to ask a question, personally, i would respect someone more if they admitted they didn't something rather than someone who thought they knew everything and end up :swear:ing it up
BTW: Welcome to HWF