HBO (Home Box Office) is an American premium television network owned by Home Box Office, Inc., a subsidiary of WarnerMedia Entertainment. Programming featured on the network consists primarily of theatrically released motion pictures and original television shows, along with made-for-cable movies, documentaries and occasional comedy and concert specials.
HBO is the oldest and longest continuously operating pay television service (basic or premium) in the United States, having been in operation since November 8, 1972.
In 1991, HBO and Cinemax became the first premium services to offer multiplexed channels to cable customers with the launches of HBO2, HBO3 and Cinemax 2 on three cable systems in Wisconsin, Kansas and Texas. In 1993, HBO became the first television service in the world to digitally transmit its signal.
The move would allow Home Box Office Inc. to launch additional multiplex channels of both HBO and Cinemax—commencing with the December 1996 launch of HBO Family and concluding with the 2001 launches of four Cinemax channels: WMax (now MovieMax), @Max (now Cinemáx), OuterMax and 5StarMax.
According to en.wikipedia