CBS (Columbia Broadcasting System) is a major television network and radio broadcaster in the United States. One of the pioneer radio networks, from its earliest days CBS established a reputation for quality; prior to the fracturing of the market under cable television, CBS's television network was one of three which dominated broadcasting in the United States.
The network is owned by the media conglomerate Viacom (itself once a subsidiary of CBS).
Les Moonves is chairman of CBS and vice-chairman of parent company Viacom. Prior to 1998, Moonves was president of CBS Entertainment.