Lyle, don't feel ignorant. Gordon, how cruel you are to mock...!
The C&AG is the head of the National Audit Office, an officer of Parliament, and sackble only by a majority vote of both Houses and with the Queen's assent. The Auditor General bit covers most of the NAO's work.
The Comptroller bit is tiny but, arguably, more important. Every Government department etc that wants to get its hands on its money 'draw down' has to ask permission from the C&AG to do so. So, the Comptroller has to authorise the release of money to Departments. The French equivalent of the NAO is the Cours des Comptes.
