HBO—also the oldest and longest continuously operating subscription television service (basic or a la carte premium) in the United States—pioneered modern pay television upon its launch on November 8, 1972: it was the first television service to be directly transmitted and distributed to individual cable television systems, and was the conceptual blueprint for the "premium channel," pay television services sold to subscribers for an extra monthly fee that does not accept traditional advertising and present their programming without editing for objectionable material.
It eventually became the first television channel in the world to begin transmitting via satellite—expanding the growing regional pay service into a national television network—in September 1975, and, alongside sister channel, Cinemax, was among the first two American pay television services to offer complimentary multiplexed channels in August 1991.
The network operates seven 24-hour, linear multiplex channels as well as a traditional subscription video on demand platform (HBO On Demand) and an eponymous streaming service (which launched as HBO Now in April 2015, and has over five million subscribers in the United States as of February 2018), and its content is the centerpiece of HBO Max, an expanded streaming platform operated separately from but sharing management with Home Box Office, Inc., which also includes original programming produced exclusively for the service and content from other WarnerMedia properties.
The HBO linear channels are not presently accessible on either streaming service but continue to be available to existing subscribers of traditional and virtual pay television providers, and as live streams to Apple, Amazon and Roku customers through streaming partnerships with those companies.
The overall HBO business unit—based at WarnerMedia's corporate headquarters inside 30 Hudson Yards in Manhattan's West Side district—is one of WarnerMedia's most profitable assets (after Warner Bros. Entertainment), generating operating income of nearly $2 billion each year as of 2017.
According to en.wikipedia