The Best Explanation of Twitter: It’s Like Working in a Cafe
While twittering is fun and simple, it is tough if you were to explain the concept of twitter to someone who has never heard of this service before.
The Common Craft team did a good job of explaining twitter in plain English with their stop-motion videos but here’s a even simpler explanation from Bill Thompson that he shared on BBC radio.
Bill says: "Twitter makes me feel like I am sitting in a cafe surrounded by lots of good friends trying to do some work over a cup of coffee. Every now and then, one of my friends would say something interesting and I can be quickly part of that conversation."

Another way to think about Twitter is a “reverse-wall”. A facebook wall shows all the inbound messages from your friends, while Twitter shows your outbound messages to the world.
Twitter is for Twits. — HoosierdaddyinFL
Yes, This is the best one I gone through.