Ooo, I thought I knew and started writing out an answer, then I did research and found out I was over simplifying it. Here is what I learned: http://forum.wordreference.com/showthread.php?t=286335
In the phrase "qu'est ce que" the "qu'est" is a "que est." Other phrases will be "qui est," but that phrase does not become a compound word.
Specifically, what "que" and "qui" mean depends on where they are in the opening of the question: " _ _ est-ce _ _ ...?"
When "qui" is in the first blank spot at the front of the question, it refers to a person. When "que" is at the front of the question, it refers to a thing.
When "qui" is in the second blank spot, it is the subject of the answer, whether or not the subject is a person or a thing. When "que" is in the second blank spot, it refers to the object of the answer, whether or not the object is a person or a thing.
Now I need to go practice some questions. Qui est-ce qui veut jouer "Questions" avec moi?