In the United Kingdom the head of state is the ruling king or queen and the head of government is the prime minister.
Britain has had a royal family for hundreds of years. When a king or queen dies, his or her oldest living male relative takes the crown. If there are no male relatives to take over, the crown passes to the oldest female relative. The new monarch receives the crown at a coronation ceremony in Westminister Abbey.
The ruling monarch's residence is Buckingham Palace. His or her offical duties include opening parliament and attending state occasions as well as representing the UK abroad on state visits.
Today, the royal family is not as powerful as it used to be, but they still have a great deal of influence over the British public.
In the USA the head of state and government is the president. The president lives and works in the White House in Washington DC. Cmp Davis is his second home and office in the Catoctin Mountains in Maryland.
The president has to perform many different roles. He has to make important decisions, meet with the leaders of other countries and control the US army.
The president can serve a maximum of two terms, which is a total of eight years, then he must step down.