Hello and welcome to the forum! For your opening post, you've provided virtually no information for us to understand your request and whether there may be other recommendations. So, please tell us: 1) Mac computer model/year; 2) OS X installed; 3) Hard Drive size (and 'free' space left); 4) What problems are you having - assume a 'slow' computer, spinning beachballs, etc; and 5) What have you done to correct your problem(s)?
As to the 'background processes' (not 'processors'), opening Activity Monitor and selecting the CPU option will show you the processes running (see the attached screen capture below) - these can be selected and stopped in a number of ways, BUT unless you really understand which ones are being 'shut down' your computer may stop working.
THUS, my suggestion is to answer my questions and let us see if there are other ways to correct your issues? Dave