Master
Master is the usual title of the head of a Cambridge College, though several Colleges use other titles, such as Provost, President, Principal, Warden or Mistress. The general term for all of them is "head of house".
In practice
King's has a Provost; Queens' and several of the newer Colleges have a President; Newnham and Homerton have a Principal; Robinson has a Warden; and Girton has a Mistress. Most heads of house are elected by the Fellows; the Master of Trinity is appointed by the Crown. Heads come from academia, public life, law, business and diplomacy, and they lead the Fellowship, represent the College and often live in a lodge within it.
Why it matters to newcomers
When writing to or introducing the head of a College, use its own title - "the President of Queens'" not "the Master of Queens'". The titles appear on invitations, formal hall seating plans and letterheads, and getting them right is noticed.
Related
- Fellow - the community the head of house leads
- College - the institution they head
- Porter and the Porters' Lodge - who will direct you to the Master's Lodge
Source: University of Cambridge.