An important feature of Parliamentary government in Canada is the Queen's Privy Council. In British history, this was a private group of advisers that gave advice to the monarch and held the secrets of the Crown. The Privy Council evolved to become the modern-day cabinet.
The Cabinet in not mentioned in the Constitution, but the Privy Council is. So the legal existence of the Cabinet really comes from the Privy Council. When Cabinet ministers are sworn into the government, they are sworn in as members of the Privy Council. In effect, the government of Canada is a committee of the Queen's Privy Council, and cabinet decisions are issued as "orders-in-council".
Privy Councillors are appointed for life. It is made up of all present and former Cabinet members, regardless of party affiliation. The full Privy Council meets rarely, usually to honour a visit by the Queen or other members of the royal family. When it meets, it assembles in the Privy Council Chamber in the East Block of the Parliament Buildings.
