Original: England has no official anthem and so uses the British National Anthem "God Save the Queen", also an unofficial anthem, for some national occasions, such as before English international football matches.
Simplified: England (as distinct from Britain) does not have an official anthem and so the British National Anthem "God Save the Queen" is used for national occasions, for example before English international football matches or at the Last Night of the Proms. The song is also the unofficial anthem of the British Women's Institute.