Question

What exactly are modern and contemporary art? For school, I have to paint a piture that relates to a certain part of speech as well as a certain type of art era/period. I'm almost finished, so now i just want to know how to EXPRESS modern or maybe even contemporary art in my painting.
Writeacher
Modern Art: http://en.wikipedia.org/wiki/Modern_Art

Contemporary Art:
http://en.wikipedia.org/wiki/Contemporary_art

Let us know if you don't see the differences.