Home is both a property of an object and a command.
The command "home" teleports a thing or player back to their home. In addition, killing a thing or player sends them home, as does destroying the room they are standing in, or dropping a thing or player that has the STICKY flag set.
Historically, "home" was an "unblockable" command, which lead to the expression "You can always go home." In modern mush servers, however, there are a variety of ways that objects can be prevented from teleporting home (such as the FIXED flag, or disabling or overriding the home command).