What is the difference between a villein and a freeman from the medieval times?

There are lots of differences between Freemen Villeins such as villeins had to stay on the lord's land all of their life and didn't get paid. On the other hand freemen got paid, and could own a small bit of the lord's land if they paid for it. Another difference is that Freemen were allowed to live where they wanted to. The villeins had to get permission for everything, from using the town oven to who they were allowed to marry. Were as Freemen were allowed to do things with out the lord's permission.