A television network is a distribution network for television content whereby a central operation provides programming for many television stations. Until the mid-1980s, television programming in the United States was dominated by a small number of broadcast networks, but with the advent of cable television the cost of creating a television network has been reduced and there have been a huge increase in the number of networks with most of the newer networks catering to a small group. Many early television networks evolved from earlier radio networks.
note: BBC NI and UTV are based in Northern Ireland, RTÉ and TV 3 in the Republic of Ireland. However all four are available to most viewers throughout the island of Ireland, with UTV now accepting advertising from the Republic and targeting some of its programmes specifically at viewers in the Republic. Access to the Republic's stations (but in particular RTÉ) in Northern Ireland was a requirement of the Good Friday Agreement peace deal in 1998.