Stars, like the sun, are sources that emit (for a portion of its life) light from its body into space. 

When light is emitted into space from a single point of origin - but that point of origin isn't a star - astronomers call that point a quasi-stellar (i.e. star) radio source, or quasar.

Quasars hit the news today because European astronomers recently discovered a quasar that's 13 billion light years away.  This compares to 1.5 light seconds from the earth to the moon and 8 light minutes from the earth to the sun.

Quasars are believed to be powered by supermassive black holes at the center.  Black holes are extremely compact and dense cores that sucks in everything in sight, including light. Supermassive black holes have masses up to the equivalent of billions of suns.

The quasar recently discovered by European scientists is believed to be 2 billion times the mass of the sun.

These supermassive black holes give out light into space when they suck in mass, which creates intense distortions and frictions in the surrounding areas (whatever is actually sucked in by the black hole, including light, doesn't escape).

This kind of light could outshine an entire galaxy of stars, said Dr Daniel Mortlock, a scientist who participated in the finding of the recent quasar, believed to be the brightest ever discovered.

Below are artist renderings of what astronomers think quasars look like.