Optical Discs
From Just Solve the File Format Problem
An optical disc is read by a laser. They have been used extensively to store and distribute music, movies, and computer programs and data. CD drives became commonplace in personal computers in the mid-1990s, and burners to create CD-ROMs on personal computers were common by the early 2000s. Later, the higher-capacity DVD format became common both for reading and writing as well, and the even newer BluRay format won a "format war" against rival HD-DVD to get some popularity at present, though physical formats in general are on the wane as a distribution format due to the widespread deployment of the high-bandwidth Internet.
