Answer: Separation of powers
The separation of powers is the doctrine that states that the power of the government needs to be separated in several branches. In the United States, these are the executive, the legislative and the judicial. The reason why the power is separated is in order to make it more difficult for any one section to overpower the rest and turn the country into a tyranny. It also allows each branch to regulate the behaviour of the other ones, in a process called "checks and balances."
