Write once read many

Write once read many (WORM) refers to any type of storage medium to which data can be written to only a single time, but can be read back from any number of times. This commonly involved an optical drive which permanently marked a reflective disk with a in order to record information. WORM media have a significantly longer shelf life than magnetic media and thus are used when data must be preserved for a long time.

History
In February 2001, Apple Computer marketed DVD-ROM drives that could "burn" recordable media as "combo drives". DVD-ROM drives that could also record media were marketed under Apple's "SuperDrive" brand.