Light Year: A light year is the distance light can travel in one year. So, it is a unit of distance (and not time). One light year is about ten million billion meters (10000000000000000 or 1016 meters; a more precise number is 9.4605284×1015 m).
kg; See kilogram.
kilogram; This is a unit of mass. A kilogram weighs about 2.2 pounds.
pound; Something that weighs a pound on the Earth has a mass little less than half a kilogram.