Appointment TV (also known as linear TV) refers to a video service that provides scheduled content - by time and by channel.
The provider of an appointment TV service will curate a long list of content that runs one after another in succession. Anyone tuning into an appointment TV service can only watch what is already scheduled for that time.
Multiple channels were later introduced to create multiple 'appointments' to satisfy the viewing requirements of different customer groups.
Until early this century, most TV service providers offered only appointment TV services. These channels have a fixed schedule on a daily and weekly basis. Cable TV and Satellite TV channels are also delivered as an appointment TV service, until recently when these channels started selling on-demand content.