What is the difference between quasars, pulsars, and neutron stars?

Hint: Pulsars and neutron stars are the remnants of the massive stars after they run out of fuel. And to be precise pulsars are a type of neutron star. Quasars are in fact defined as the astronomical object which is very larger than the pulsar and also has very high luminosity. These quasars are found in the center of the galaxies.

Complete Step By Step Answer:
A pulsar is defined as a star that radiates a beam of electromagnetic radiation like radio waves. Its size is a very small and very dense compact star that rotates rapidly, emitting regular radio waves.
When a massive star runs out of fuel and collapses neutron stars are created. This neutron star is created when the core of the star collapses and crushes every proton and electron into a neutron.
Quasars are also called quasi-stellar radio sources. But actually, quasars are not stars. They are now called young galaxies. It is located at a very vast distance from us. They are visible to us even when they are too far from us because they are up to a thousand times brighter than our own Milky Way galaxies.
Now the differences between these three stars are mentioned below.
-As we already said quasars are not stars whereas pulsars and neutron stars are the remnants of the star. We call an astronomical object a star when they fuse hydrogen into helium in their cores. Pulsar and neutron stars are the remnant of stars that once did this nuclear fission.
-Neutron stars are said to be one of the densest objects. Most of the neutron stars that are observed are pulsars. Pulsars are called rotating neutron stars. Many neutron stars are very difficult to detect as they do not emit enough radiation. The pulsar has higher magnetic fields than the neutron stars.
-Quasars are found very far away than the neutron stars and the pulsar.
-Quasars are generally associated with a black hole, while neutrons and black holes are not associated with it.

Note:
Quasars can be found over a wide variety of distances. Quasar detection surveys have shown that quasar occurrence was more frequent over the past. Nearly about ten billion years ago, quasar activity was at its peak. When a pulsar is newly formed, it is found that it contains very high energy and has the fastest rotational speed. As it starts to release the electromagnetic power through its beams, its rotational speed gradually slows down.