Parliamentary system of government is defined as a system of government in which the head of state is distinct from the head of government. Both offices and functions attached to them are in the hands of two individuals, unlike the presidential system where the two offices (head of state and government) are fused.
The head of state exercises ceremonial functions. The prime minister is the head of government and he exercises executive functions. The prime minister and his cabinet are drawn from the parliament, making them members of the executive as well as the parliament. The prime minister is the chairman in all cabinet meetings.
In Britain, for example, the head of state is the Monarch (Queen). In a country that is not a Monarchy, the head of state is the president. Britain has a cabinet or parliamentary system of government.
Functions of the Opposition Party in a Cabinet System of Government
The existence of opposition party in a cabinet system of government is legal and officially recognised. It is the party that has the second highest number of seats in the parliament.