"Awesome" is actually overused. Used today, it means very good, cool, as Siny Adon says. It should mean incredible, almost beyond the imagination, which is its original definition.
The Grand Canyon in the U.S. is awesome. Most of what other people call awesome is just "impressive".
One note: Sometimes you will hear "awesome" used in a sarcastic manner.
[Someone trips and falls with a dinner plate']
"Oh, that was just awesome!"