Hard Disk Drives HDDs

A hard disk drive (HDD) is a magnetic storage device. It stores data using magnetism on surfaces inside the drive, so it belongs to the magnetic type of storage.

HDDs offer high capacity, so one drive can hold a very large number of files, such as a family's whole collection of photos and videos. Their speed is medium: they are slower than solid state storage, so an SSD loads programs more quickly, but they are faster than optical storage. They also have a low cost per gigabyte, which makes them a cheap way to store lots of data.

Moving parts bring risks

An HDD contains moving parts that work while the drive is running. A drop or knock can damage these parts, especially if the drive is being used at the time. The movement also means the parts wear out over time. Strong magnets placed near an HDD can damage the data too, because the data is stored magnetically.

Fixed or portable

An internal HDD is fixed inside a computer and is not designed to be carried around. An external portable HDD can be connected by a cable and moved between places, but it is larger and heavier than flash storage such as a USB flash drive. If you need to carry a lot of data in a pocket, flash storage is easier to carry. If you need lots of space at low cost and the drive can stay in one place, an HDD is a good fit.