Simplify the following text for a Grade 12 native English-speaking person.
Original: In the United Kingdom , `` unitary authorities '' are English or Welsh local authorities set up by the Local Government Act 1992 which form a single tier of local government , and are responsible for almost all local government functions within their areas .
Simplified: In the United Kingdom , `` Unitary Authorities '' are English councils which are responsible for almost all local government functions within their areas .