Differences

Quasars, pulsars, and black holes are a few of the many, many things found in the Universe.
In scienific terms, a quasar is a very energetic radio source and distant galaxy with a active galactic nucleus. In other words, they are the most brightest and distant objects in the Universe. They are not actually stars, but emit a lot of energy at one time. Quasars are located in the center of a massive galaxy which surrounds the super massive black hole. Not much is known about quasars, and they remain somewhat of a mystery to scientists.
Pulsars are rotating nuetron stars which are highly magnetic, and emit a beam of electromagnetic radiation. They are known to be one of the strangest things in our universe. They are given their name because of the radiation pulses they give off, which can only be observed when directed at earth. Pulsars form when a massive star collapses and it blasts out into a supernova. Some pulsars can be seen with visible light, and are found with large radio telescopes.
Blackholes are a region in space where nothing can escape, not even light beams. They are thought to form from explosions of super massive stars. It slowly tears pieces into smaller and smaller objects, and the gravity within black holes is very strong. The event horizon, also known as the point of no return, is an undectable surface which surrounds the black hole. Black holes are found at the center of galaxies.
These are a a few of the many puzzling things found in our universe.