A volume may refer to any of the following:
1. When referring to sound, volume refers to the amplitude of the sound being projected from a speaker. As seen in this picture, two knobs change the volume level: one controls the subwoofer, and one controls the main (overall) sound volume.
2. When referring to data storage, a volume refers to a logical drive (e.g., hard drive), which has a single file system and is usually on a single partition. For instance, on a typical Microsoft Windows computer, the volume named C: contains the operating system. In Windows, any drive which has an assigned drive letter is a volume.