This is a common technique by which closely related commands that have been packaged as a unit allow the user to specify the particular course of the intended action.
[3] The version of mv bundled in GNU coreutils was written by Mike Parker, David MacKenzie, and Jim Meyering.
[4] The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities.
On platforms that do not support the rename syscall, a new link is added to the new directory and the original one is deleted.
An actual move (effectively a rename) is dramatically faster than the circuitous copy-and-move procedure.
Most versions of mv support: These options are a part of X/Open Portability Guidelines, later the basis of POSIX and SUS.
A "file system" can be thought of as an independent tree that is logically regarded as a unit; its root is "mounted" atop a directory of the administrator's choice.