Cosmic background radiation

In astronomy,  there are a number of different kinds of background radiation in the universe. One of most popular interest is called Cosmic microwave background (CMB).  

There are few others that are less known or less significant such as  radiation in the infrared, x-rays, etc., with different causes, and they can sometimes be resolved into an individual source.

For example:

  •  cosmic infrared background
  • X-ray background 
  • Cosmic neutrino background 
  • extragalactic background light.