Opposite is chaos , or disorder.
Cosmology is the study of the order in the universe.
We take seemingly disparate, disordered phenomena and try to find the underlying order. General idea we have is that the universe is made of matter and energy which behave according to certain physical laws . On the small scale, matter consists of fundamental particles, which interact with one another. Energy is associated with forces between the particles. In cosmology, however, we need to use General Relativity.