ROM (Read-Only Memory)

ROM is a form of memory in which data cannot be changed once it has been entered. The computer can read, but cannot rewrite the contents. ROM memory chips supply constant code elements such as bootstrap loaders, network addresses, and other more or less unvarying programs or instructions.

It should be noted that MS-DOS files can be made read-only by the addition of a read- only attribute +r, as with: C:\ attrib +r filename.txt.

W3E References:

CD-ROM (Compact Disk-Read-Only Memory)

A hardware format utilizing compact disks for memory storage, capable of storing 650 MB of data per disk.