The Chamber of Local Authorities is composed of representatives of local bodies who either hold a general local authority mandate resulting from direct elections or are politically accountable to a directly elected assembly.
(Charter, art. 2.1)

The Chamber of Regions is composed of representatives of regional bodies at a level between central government and local authorities and enjoying prerogatives either of self-organisation or of state-like powers.
(Charter, art. 2.1 & 2.4)