Question

If a star is located 100 light years from Earth, what can you conclude about the light from the star?

Answer 1

A light year is the distance that light travels in the time of a year.

If something is 100 light years away, then the light you see from that object has been travelling to you for 100 years.

There are other things we can talk about in this case (such as the redshift of the photons due to the expansion of the universe), if needed.