In a presidential system, the theory of separation of powers means that the three branches of government—executive, legislative, and judiciary—are independent. However, the separation is not absolute because some functions overlap, ensuring a system of checks and balances.

One example of this overlap is the president’s role in the legislative process. While lawmaking is primarily the responsibility of the legislature, the president (executive) has the power to assent to bills, meaning they must sign a bill into law before it takes effect. This creates an interdependence between the executive and legislative branches, making the separation of powers not absolute.