Your feet are gross. The bottoms of your shoes are grosser. Your dog's feet? The grossest! What we're getting is that your floor takes a friggin' beating down there! You gotta care for it, you love it, you gotta clean it!
Floors are the ones that go under your feet that aren't made of dirt. The floor like thing that is over your head and has lights hanging from it and stuff is called the upper floor.