A light year is the average time it takes stars to travel around the centre of the Galaxy.

A light year is the distance that light travels in one year.

A light year is the time it takes light to travel a certain distance.

A light year is 2.998 x 10^8 m/s.

A light year is a made-up term used in Star Wars.

A light year is the average time it takes light to reach us from the Sun.

A light year is typically used to denote the distances to very far objects.