Elves do not understand the concept. Freedom is taken for granted. Humans are often used as slaves as are any other creature. Dwarves from upon slavery. Criminals are forced into farming.
Slavery is rare, but does occur.
Heldann Farmers are serfs. Not much different from slaves. Some eccentric knights keep slaves which they have imported from Hattias. Norwold Slavery is legal, but not very common. Slavery is illegal.