The document discusses the history and aims of public service broadcasting (PSB) in the UK. It explains that the BBC was the first PSB and was established to inform, educate, and entertain without commercials. When ITV launched in 1955, it was also given PSB obligations around local news and programming. Channel 4 and S4C were later established as alternative PSB options with obligations around catering to minorities. The document examines how political, cultural, and economic contexts influence what counts as PSB.