Answer: Light years is a form of measurement like km
Explanation: light years is the speed of light which is 299792458 meters a second but for earth years for example 1 light year is 365 normal days Which is 8760 hours which is 525600 minutes which is 31536000 seconds
so 31536000 x 299792458 is 9,454,254,955,488,000 meters a year which to simplify it and not needing to say that many numbers we say one light year.
