Alright, kiddo. Have you ever seen a field that nobody is using or taking care of? Maybe it's just land with no crops or buildings on it. Well, the homestead principle says that if someone comes along and starts using that land for something useful, it becomes their property.
It's kind of like finding a toy on the playground that nobody is playing with. You can claim it as your own and keep it as long as nobody else comes along and starts using it.
This idea was especially important in American history when people were moving West and needed to claim land to build their homes on. The Homestead Act was passed in 1862, which gave people the chance to claim up to 160 acres of land and turn it into a farm or ranch.
So, the homestead principle basically means that if nobody is using something, and you start using it in a productive way, it's yours to keep!