Technically speaking, a self-employed move is any residential move that doesn't involve a full-service moving company sending two or more strong workers to load all their stuff into their truck and then reversing the process in their new home. But that doesn't mean there aren't any outside companies involved at all. When making a self-service move, you'll need to pack all your belongings yourself. You'll also have to load and unload the truck yourself and unpack everything when you get to your new home.
This can be a lot of work and be physically demanding. Able to move without an outside agency.