A hard drive is a crucial hardware device in a computer that stores digital content and data permanently. It retains all of your files—such as photos, videos, music, documents, and applications—as well as the operating system and other essential software. Hard drives use either magnetic disks (in traditional Hard Disk Drives, HDDs) or flash memory (in Solid State Drives, SSDs) to save and retrieve data. This storage is non-volatile, meaning the data remains intact even when the computer is turned off. Essentially, the hard drive functions like a long-term digital filing cabinet that holds all the information your computer needs to operate and store your personal files over time. Internal hard drives are built into the computer, while external hard drives can be connected for additional storage, backups, or file transfer purposes.