The acronym "ROM" stands for "Read-Only Memory." This term is used in regards to computers and compact discs that cannot be written over, only read.
The most common form of Read-Only Memory in a computer is the "BIOS," which stands for "Basic Input/Output System." The BIOS is read at the start-up of a computer. CD-ROMs often contain information or a program that can be read by or ran by the computer. This information is normally put onto the disc at a factory; however, if a computer has a disc burner, then the user can also burn information onto a CD-ROM as a way to back up files or make a music CD.