This is Why I'm Not an Economist

Got the following Yahoo! News Alert today:

NEW YORK (AP) A private research group says that a measure of activity for the non-manufacturing sector of the U.S. economy grew at a sharply lower rate in September.

So... what happened? What "activity"? What's the "non-manufacturing" sector? Retail, financial, and health services - anything else? What the hell does "grew at a sharply lower rate" mean? The rate at which it grew was different than a previous rate?

Meh.

Tags: definition, economics, words