The Cabinet is the group of twenty or so senior government ministers who are responsible for running the ministries and departments of state and decide government policy.
Cabinet ministers are appointed by the prime minister and chosen from MPs or peers of the governing party.
Chaired by the prime minister, cabinet is bound by collective responsibility, which means that all its members must abide by and defend the decisions it takes, in spite of any private or personal doubts they might have.
The conventions of collective cabinet responsibility and the power of prime ministerial control in cabinet have developed over the centuries.
In the 18th century William Pitt confirmed the right of the prime minister to appoint ministers and more importantly, to ask them to resign.
The cabinet usually meets once a week in the Cabinet Room in Downing Street.
Cabinets have met in the same room in since 1856.
During periods of national emergency, or when no single party gains a large enough majority to govern alone, coalition governments have been formed with cabinets containing members from more than one political party.
War cabinets have sometimes been formed with a much smaller membership than the full cabinet.
From time to time the prime minister will reorganise the cabinet in order to bring in new members, or to move existing members around. This reorganisation is known as a cabinet re-shuffle.
The cabinet normally meets once a week in the cabinet room at Downing Street.