Hey, you're a busy man right? Or a busy woman. I'm not discriminating.
Point is, sometimes you need to know about something (frogs, bananas, helicopters, jazz, batman, electricity, beer) in a hurry. Firing up wikipedia is all well and good, but it's just not quick enough.
You haven't got time for history lessons or uses in popular culture. You just need the essence of your chosen subject.
Step up, 10 Word Wiki.
If it can't be explained in 10 words, you don't need to know about it.