And what did you get when you looked up "kinetic theory" on wikipedia?
I think that textbooks must be a better place to look.
That Wikipedia article is the typical mixture of confusion and/or lack of rigour. It starts saying that the kinetic theory of gases describes a gas as a number and continues saying that all atoms or molecules in a gas are in constant random motion. I wonder what it means by constant.
Moreover, the article mixes kinetic theory with the kinetic theory of gases, and this with the kinetic theory of ideal gases. E.g. the postulates are only for the latter...