The separation of powers, often imprecisely used interchangeably with the ''trias politica'' principle, is a model for the governance of a state (or who controls the state). The model was first developed in ancient Greece. Under this model, the state is divided into branches, each with separate and independent powers and areas of responsibility so that the powers of one branch are not in conflict with the powers associated with the other branches.
More at: Separation of powers
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