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.
Compared with a typical parliamentary system: 1  The legislature in a presidential system is in a better position to oversee the actions of the president and executive agencies. 2  A parliamentary system with a majority government should be able to put their program into law; a president facing an opposition legislature is a recipe for deadlock.