The distance from the earth to the moon is 1.25 light seconds, which is roughly 238,900 miles. Light years are reserved for dealing with massive distances in outer space.
One light year is the distance that light can travel in one year. To understand the vastness of the universe, it helps to look at it in light years. For example, if a star is 4.22 light years away, which is true of the closest star (other than the sun) to earth, then it takes light from that star 4.22 years to reach earth. By comparison, the sun is 8.32 light minutes from Earth.