Dividing governmental authority among distinct branches prevents the concentration of power in a single set of hands. Separation of powers assigns lawmaking to the legislature, execution to the executive, and adjudication to the judiciary.

Pure separation is rare; most systems include checks and balances that give each branch some influence over the others. Presidential systems approximate separation more closely than parliamentary ones, where the executive depends on legislative confidence. The underlying purpose is to protect liberty and force deliberation.

Tensions among branches are expected and even desirable when they prevent hasty or oppressive action. Gridlock can result when partisan control is divided and incentives to cooperate are weak. Constitutional design and political culture together determine whether separation produces balanced government or chronic stalemate.

• Division of authority among legislative, executive, judicial branches
• Aims to prevent concentration of power
• Accompanied by checks and balances
• Shapes the character of presidential systems especially