Also see volume (amount of physical bulk).
1) In computers, a volume is an identifiable unit of data storage that is sometimes (but not always) physically removable from the computer or storage system. In tape storage systems, a volume may be a tape cartridge (or, in older systems, a tape reel). In mainframe storage systems, a volume may be a removable hard disk. Each volume has a system-unique name or number that allows it to be specified by a user.
In some systems, the physical unit may be divided into several separately identifiable volumes.
2) In audio, volume is the loudness of the signal.