Need & separation of powers

Separation of powers is a doctrine of constitutional law under which the three branches of government (executive, legislative, and judicial) are kept separate. This is also known as the system of checks and balances, because each branch is given certain powers so as to check and balance the other branches. Separation of powers, therefore, refers to the division of government responsibilities into distinct branches to limit any one branch from exercising the core functions of another. The intent is to prevent the concentration of power and provide for checks and balances. The system of separation of powers divides the tasks of the state into three branches: legislative, executive and judicial. These tasks are assigned to different institutions in such a way that each of them can check the others.