This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Please SearchFirst(⇐click), and then, if, after spending sufficient time researching, you have specific questions, post again. Make sure to TellTheDetails(⇐click) about the context in which you saw the term, what you found, and what specifically you still don't understand.