There are two types of radio networks currently in use around the world: the one-to-many broadcast type commonly used for public information and entertainment; and the two-way type used more commonly for public safety and public services such as police, fire, taxis, and delivery services. Following is a description of the former type of radio network although many of the same components and much of the same basic technology applies to both.
The Broadcast type of radio network is a network system which distributes programming to multiple stations simultaneously, or slightly delayed, for the purpose of extending total coverage beyond the limits of a single broadcast signal. The resulting expanded audience for programming or information essentially applies the benefits of mass-production to the broadcasting enterprise. A radio network has two sales departments, one to package and sell programs to radio stations, and one to sell the audience of those programs to advertisers.
Most radio networks also produce much of their programming. Originally, radio networks owned some or all of the radio stations that broadcast the network's programming. Presently however, there are many networks that do not own any stations and only produce and/or distribute programming. Similarly station ownership does not always indicate network affiliation. A company might own stations in several different markets and purchase programming from a variety of networks.