What is Parliament in simple terms?

Parliament is the supreme law-making body of the United Kingdom, made up of three parts: the elected House of Commons, the appointed House of Lords, and the monarch acting as head of state.

The Commons contains 650 Members of Parliament, each representing a single geographic constituency and elected by the first past the post system. The Commons is the senior chamber and is where the government of the day is formed. By constitutional convention, the Prime Minister must be able to command a majority there. The House of Lords contains around 800 peers, made up mostly of life peers appointed by the monarch on the advice of the Prime Minister, 92 remaining hereditary peers, and 26 Lords Spiritual, who are senior bishops of the Church of England. The Lords revises legislation, scrutinises government, and brings in specialist expertise, but its powers are limited. The monarch's role is almost entirely formal. The sovereign opens each session with the King's Speech, gives Royal Assent to bills, and prorogues or dissolves Parliament on the advice of ministers.

Parliament has three main jobs. It makes laws by passing bills through both Houses. It raises and scrutinises taxation, a power that has lived with the Commons since the seventeenth century and is protected by the convention that money bills cannot be blocked by the Lords. And it holds the government to account through debates, written and oral questions, and the Select Committee system.

The doctrine of Parliamentary sovereignty means that, in constitutional theory, no Parliament can bind a future Parliament and no other body can override an Act of Parliament. In practice, the Human Rights Act 1998, devolution settlements for Scotland, Wales, and Northern Ireland, and obligations under international law all shape how that sovereignty is exercised.

Parliament meets in the Palace of Westminster on the banks of the River Thames in central London. The present building was designed by Charles Barry and Augustus Pugin after the original burned down in 1834. Its origins lie in the medieval Great Councils summoned by Norman and Plantagenet kings. The two-chamber structure emerged in the fourteenth century, when the knights of the shires and burgesses of the towns sat separately from the lords. The Glorious Revolution of 1688 and the Bill of Rights of 1689 established Parliament's supremacy over the Crown.