What is art?

I have always wondered what art is. Two lines and a dot, is art, if Picasso painted it, but if I painted it, it nothing. Why is ballet an artform and not a sport? Maybe it's because ballet is artificial. You do the unatural with your body.
   Art is only there to show it to people. Dance is a form of entertainment. Art has no use in "real life". Art is useless. Perhaps that is the definetion of art: Something useless, that gives pleassur to other people, and is extremly hard to make.... I really don't know. 
   Dancers create art with their bodys, painters with a brush, musicians with sheet music. Art can be created by anything. But why is not everything art then??

Art, questionmarks and kisses,
- Me <3