What is a medium when talking about a art painting?

Question:

What is a medium when talking about a art painting?

i am doing a reaserch of 21 artist and i have to describe one piece of art that they had done and say what the medium is, but i dont know what that is! help!

the pieces are paintings, sculptures......

Best Answer - Chosen by Asker:

In the arts, media (plural of medium) are the materials and techniques used by an artist to produce a work.

http://en.wikipedia.org/wiki/art_medium...