Paper is usually made from very finely ground up wood, bleached white. Paper is thin, usually smooth, and is used to make books, newspapers, magazines and of course you can buy blank or lined paper to draw or write on.
Pieces of paper come in lots of different sizes, textures and colours. Rougher paper is better for drawing on in pencil or charcoal. Paper can be cut or folded into different shapes, for crafts like origami.