Simplify the following text for a Grade 10 native English-speaking person.
Original: Parliamentary systems usually have a clear differentiation between the head of government and the head of state , with the head of government being the prime minister or premier , and the head of state often being a figurehead , usually either a president ( elected either popularly or by the parliament , a Parliamentary republic ) or a hereditary monarch ( or representative thereof such as a Governor-General ) , often seen in a constitutional monarchy .
Simplified: Parliamentary systems usually have a head of government and a head of state . The head of government is the prime minister , and the head of state often being an elected ( either popularly or through parliament ) president or hereditary monarch .