Computer memory, device that is used to store data or programs (sequences of instructions) on a temporary or permanent basis for use in an electronic digital computer. Computer memory is of two basic types €“ Primary memory(RAM and ROM) and Secondary memory (hard drive, CD, etc). Random Access Memory (RAM) is primary-volatile memory and Read-Only Memory (ROM) is primary-non-volatile memory. A compact disc recordable (CD-R) is a writable disc upon which a user can write once and read many times. Additional InformationCD€“Read Writable (CD-RW) refers to an optical CD that may be written and rewritten multiple times.