You seem to be a beginner so i will offer you actual help instead of mocking you.
To run a game well you need to have an appropriate processor (decent quadcores are sufficient for nearly all games nowadays), a good graphics card (the better your graphics card the faster your games run, basically) and of course enough ram (system memory). But often games run with less memory than one would expect - for example this 350$ system put together with a first generation intel core i5, an Nvidia GTX 760 and only 4 gigabytes of RAM has no trouble running GTA 5 on high at 60 fps.
youtube.com/watch?v=DH6FCgqQB_s