Answer:
The Separation of Power
Step-by-step explanation:
The Separation of Power refers to the division of power and responsibilities of the government into different branches or bodies, therefore, the phrase "each branch of the government has different duties" refers to this concept.
In the United States and in many other democratic nations, the power of the government is divided into the Judicial, the Executive and the Legislative branches. This principle also sets the basis for the Checks and Balances system in which all branches oversee, check and limit the power the other in order to fulfill the purpose of the "Separation of Power:" to prevent any one branch from becoming too powerful.