Radio has evolved dramatically since the first broadcasts in the 1920s.
As a media industry it was dominated by the BBC until the 1960s when pirate radio stations became popular with young people.
This popularity would pave the way for commercial radio to establish itself and allow the industry to develop.
Modern radio is available in various forms:
BBC Radio 1 DJ Nick Grimshaw
A radio programme's style and content will be influenced by the station identity and often by the personality of the presenter.
Programmes can be broadcast live or be pre-recorded.
For example, The Radio 1 Breakfast Show with Nick Grimshaw is a live presenter-led show which contains the expected conventions of music, chat, guest interviews, an audience phone-in and competitions.
The show is zoo format; this means it includes all those elements mentioned and is delivered in a spontaneous, comic way.