Smallville is a small town in the DC Universe and was the hometown of Clark Kent.
A city in Kansas coomonly known for being Superman's hometown.
When Superman was launched from Krypton to Earth, in landed in a farm in Smallville the farmers there always wanted a son so they raised him and hide the spaceship he came from. Later Superboy moved in there and he became protector of that City after Superman left for Metropolis.
It is also the name of the show when it was Superman's city.