A directory on one volume that an application can use to mount a different volume, that is to set it up for use at the location a user specifies. In other words, you can use a mount point as a gateway to the volume. When a volume is mounted at a mount point, users and applications can refer to the mounted volume by the path of the mount point or a drive letter. For example, with a mount point set the user might refer to drive D as "C:mntDdrive" as well as "D:".