HD may refer to any of the following:
1. Abbreviation used for hard drive, although more commonly abbreviated as "HDD" for hard disk drive.
2. Short for high-definition, HD is used to describe a device, video, or audio that is the absolute best in quality, especially when compared with SD (standard-definition). See the HDTV definition for further information and related links.
3. HD is a device name for hard drive.