Mac OS X: What Are All Those Processes?

Mac OS X: What Are All Those Processes?:

Mac OS X (like any unixish OS) always has a number of things going on in the background — processes that take care of business behind the scenes. Normally, you won’t even notice them, unless you use something like ProcessViewer or the ps or top commands to look at the process list. If you do notice them, you may wonder what on earth they’re all there for. This list is here to answer that question.