What is the unit of distance used to measure how far away something is in space?

most objects in space are so far away, that using a relatively small unit of distance, such as an astronomical unit, is not practical. Instead, astronomers measure distances to objects which are outside our solar system in light-years

Light years or something like that, idk how to spell it lol

i think that it's radiating electro magnetic radiation

some bombs actually use electromagnetic radiation in a emp (electromagnetic pulse) to disable electronics and antennas.