Optical Discs

An optical disc consists of a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser

Optical discs commonly store items in a single track that spirals from the center of the disc to the edge of the disc

Track is divided into evenly sized sectors

A CD-ROM can be read  from but not written to

-Single-session disc

A CD-R is an optical disc on which users can write once, but not erase

A CD-RW is an erasable multisession disc 

A DVD-ROM is a high-capacity optical disc on which users can read but not write on or erase

A DVD-R or DVD+R are competing DVD-recordable WORM formats, on which users can write once but not erase

DVD-RW, DVD+RW, and DVD+RAM are high-capacity rewritable DVD formats