What Is ROM (Read-Only Memory)?

Read-only memory (ROM) is a subtype of the primary (main) computer memory containing data that can only be read, not altered or deleted.

The typical use of ROM is to store boot firmware, such as the basic input/output system (BIOS) and unified extensible firmware software (UEFI). However, ROM is also used in consoles and optical storage devices (for example, CDs).

Data stored on a ROM chip is non-volatile – the chip does not require a continuous power supply to retain and use the data.