UK: head of state, parliament, government

The British government runs the UK. Prime Minister is theh leader of thr government.

David William Donald Cameron is the current Prime Minister of the United Kingdom, First Lord of the Treasury, and Leader of the Conservative Party.

Elizabeth II is the reigning queen and head of state of 16 independent sovereign states.

Government(Executive)

The government runs the country. Government also has responsibility for developing and implementing policy and for drafting laws. Every day the Queens desk is full of documents and reports from the government ministers and commonwealth officials. They must all be read and if necessary singed by the queen.


Parliament(Legislature)

The highest legislative authority in the UK is the Parliament. Its responsibility is checking the work of government and examining, debating and approving new laws.

Monarch

A person who heads a monarchy is called a monarch. Monarchs may be autocrats or ceremonial heads of state. In wich a country or entity is usually ruled or
controlled by an individual who exercise little or no power,actual authority vested in a parliament or other organisations. Most states only have a single monarch at any given time.


Source (in order of appearance):
http://www.parliament.uk/about/how/role/parliament-government/
http://www.projectbritain.com/government.html
http://en.wikipedia.org/wiki/Monarch

I tried, the links still won`t work!