These are customs and political habits which have developed over a number of years and have became accepted practice.

Although the constitution is unwritten, some parts are written down in acts of parliament

This is ancient rules and customs now seen as accepted common practice.

Opinions expressed in such works do not have the force of law, but are used by judges in particularly difficult cases.

these now form part of the British constitution, because EU law takers precedence over British Law, where there is conflict between the two.

Parliament can make/ unmake any law it likes, no other body can make laws without parliament's permission.

All political authority resides with the central government at Westminster

The government must act within law; citizens can seek redress through the courts, if they believe the government has acted beyond its powers; in return citizens must obey the laws passed by parliament.

The Queen is head of state, she heads both parliament and the government, but she has no political power, the PM is appointed by the Queen, but by convention, she must choose the leader of the largest party after an election.