LaserDisc

LaserDisc (LD) is a home video format and the first commercial optical disc storage medium.

Optical discs can be reflective, where the light source and detector are on the same side of the disc, or transmissive, where light shines through the disc to be detected on the other side. They may contain analogue or digital information, or a mixture of the two.

LaserDiscs stored analogue video using a composite signal format, offering picture quality comparable to the 1-inch (25 mm) Type C videotape format, with a resolution of 425 to 440 TV lines .

The core difference between LaserDisc and CED: LaserDisc reads data optically with light and has no physical wear; CED reads data mechanically with a physical stylus in a groove, much like an evolved vinyl record, and does wear out. That's a big part of why LaserDisc had the better reputation for picture quality and durability, while CED was cheaper but declined faster — RCA discontinued CED by 1986, while LaserDisc survived commercially into the early 2000s.