ROM

Read-only memory (ROM) is a type of memory that cannot be written to. Information is written to ROM chips by the manufacturer, and this information cannot be changed. In the past, if ROM information needed to be updated, you had to remove the original chip and replace it with an updated ROM chip. Software written to ROM chips is called firmware.

Types of ROM: Read Only Memory, Programmable Read Only Memory, Erasable Programmable Read Only Memory, Electrically Erasable Programmable Read Only Memory, and Flash Electrically Erasable Programmable Read Only Memory.