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.
Presidential Gov't Parliamentary Gov't Both are democratic type governments. Both are able to overrule and get rid of their leaders. Both leaders roles (president and prime minister) are sorted in the executive branch. The president serves as both the chief of executive and the head of state. The head of state and chief executive are two different people. The chief executive is chosen by the legislature, while the head of state serves for a more ceremonial purpose. The president is chosen by the people, not the legislature. Party members almost ALWAYS vote for their party leader.