A 5.25" storage drive that takes up half the vertical space of first-generation drives in desktop computers. Measuring 1 5/8" in height, it was commonly used for 5.25" floppy drives and hard drives. Floppy drives are history, and hard drives today are 2.5" and 3.5". However, the half-height 5.25" form factor is still used for CD/DVD drives and certain tape drives. Contrast with full-height drive.