I did correct that you were wrong. I just didn't explain the correct definitions mainly because I don't like to write long messages on mobile. But to prove how much I am in pain, I googled it for you: http://en.wikipedia.org/wiki/Compute...2Ftime-sharing My main issue was that you mixed the terms. Minor point is that, luckily, cooperative multitasking is not probably used in any current operating system.