This refers to leaving a specific house or apartment, often because you're relocating to another place or living on your own.
move out
to cause someone or something to fall to the ground by hitting him, her, or it
knock down
This means to leave a place, usually your hometown or a place you've lived for a while, and go somewhere else, often far away. It's more about distance and leaving behind a place.
move away
Unlock this slideshow and over 4 million more with Baamboozle+