The Sumerians were the first people to migrate to Mesopotamia, they created a great civilization. Beginning around 5,500 years ago, the Sumerians built cities along the rivers in Lower Mesopotamia, specialized, cooperated, and made many advances in technology. The wheel, plow, and writing (a system which we call cuneiform) are examples of their achievements.
1 In a Parliamentary System, the head of state is usually a different person than the head of government (not in every country). 2  The HOG is often vested with more official power, but holds that position for a relatively short time.
Parliamentary democracy is a representative democracy where government is appointed by, or can be dismissed by, representatives as opposed to a presidential rule wherein the president is both head of state and the head of government and is elected by the voters.residential Democracy is a system where the public elects the president through free and fair elections. The president serves as both the head of state and head of government controlling most of the executive powers. The president serves for a specific term and cannot exceed that amount of time.