A HHD (hybrid hard drive) is a storage device that is a combination of an SSD (solid-state drive) and an HDD (hard disk drive). Its intended purpose is to bring together the performance of an SSD with the affordability and high capacity of an HDD. A hybrid hard drive may combine two drives (one SSD, one HDD) into the same computer system. Or, it may be a SSHD (solid-state hybrid drive), combining an SSD and a hard disk drive into a single device, as shown below.
A key element of this type of hybridization is deciding what kind of data should be prioritized for which type of storage. This prioritization can be performed manually, or automatically by the operating system or the device itself. As SSD only hard drives continue to become lower in price hybrid drives popularity is decreasing.
Hard drive terms, Storage device
The abbreviation “HHD” is also often a misspelling for “HDD”. See our hard disk drive definition for a full definition of an HDD (hard disk drive).