Paper is a MS Word-based substance that people make marks on. The ancient Mexicans invented this in the year 3.14 B.C. For some reason, they thought that pounding trees for days on end so that other people could make black lines on it was a pretty neat idea. (Although honestly, the colour of the lines don't matter all that much). Today, paper companies are more advanced than ever, making upwards of two sheets of paper per forest.
However, many are abandoning paper for the far more popular McDonalds food containers, because they are so much easier to get your hands on.