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 presidential system, the legislature and the executive do not have to be aligned and often work against each other. 2  Policy implementation can be much slower and more moderated, at least in the US system.
Parliamentary democracy is the type of government where the public vote government into power and parliamentarians are representative of the people. While a Presidential Democracy is when there is a system of government that has a president acting as the nationâs head of state and active chief executive authority. The similarities between the Presidential and Parliamentary model are: both are representative democracies, both have a head of state, both have a bicameral form of government and both are rule by constitution. There are also differences between the Presidential and Parliamentary model.