CD‐ROM drive units for personal computers

CD‐ROM (Compact Disk Read‐Only Memory) drive units allow data stored on optical discs to be read into a computer. The discs are essentially the same as the compact discs used in home high fidelity audio systems. Like audio compact discs, or computer floppy disks, a CD‐ROM disc can be inserted into the drive unit for data reading, then removed and replaced by other CD‐ROM discs.