Separation of powers

Separation of powers refers to the division of a state's government into "branches", each with separate, independent powers and responsibilities, so that the powers of one branch are not in conflict with those of the other branches. The typical division into three branches of government, sometimes called the trias politica model, includes a legislature, an executive, and a judiciary. It can be contrasted with the fusion of powers in parliamentary and semi-presidential systems where there can be overlap in membership and functions between different branches, especially the executive and legislative.

The intention behind a system of separated powers is to prevent the concentration of power by providing for checks and balances. The separation of powers model is often imprecisely and metonymically used interchangeably with the trias politica principle. While the trias politica model is a common type of separation, there are governments that have more or fewer than three branches.