First: The legislative power The legislative branch of government is responsible for making and enacting the laws of the state and appropriating the money necessary to operate the government.

A legislature is the law-making body of a political unit, usually a national government, that has power to amend and repeal public policy. Laws enacted by legislatures are known as legislation. Legislatures observe and steer governing actions and usually have exclusive authority to amend the budget or budgets involved in the process. Names for national legislatures include "parliament", "congress" and "assembly". The members of a legislature are called legislators.

A legislature is composed of one or more deliberative assemblies that separately debate and vote upon bills. These assemblies are normally known as chambers or houses. A legislature with only one house is a unicameral legislature, while a bicameral legislature possesses two separate chambers, usually described as an "upper house" and a "lower house".

Second: The executive power The executive branch is responsible for implementing and administering the public policy enacted and funded by the legislative branch.

The executive is the organ that exercises authority in and holds responsibility for the governance of a state. The executive executes and enforces law.

In political systems based on the principle of separation of powers, authority is distributed among several branches (executive, legislative, judicial) — an attempt to prevent the concentration of power in the hands of a small group of people. In such a system, the executive does not pass laws (the role of the legislature) or interpret them (the role of the judiciary). Instead, the executive enforces the law as written by the legislature and interpreted by the judiciary. Executive bureaucracies are commonly the source of regulations.

Third: The judicial power The judicial branch is responsible for interpreting the constitution and laws and applying their interpretations to controversies brought before it.

The judiciary (also known as the judicial system or court system) is the system of courts that interprets and applies the law in the name of the state. The judiciary also provides a mechanism for the resolution of disputes. In some nations, under doctrines of separation of powers, the judiciary generally does not make law (which is the responsibility of the legislature) or enforce law (which is the responsibility of the executive), but rather interprets law and applies it to the facts of each case. In other nations, the judiciary can make law, known as Common Law, by setting precedent for other judges to follow, as opposed to Statutory Law made by the legislature. The Judiciary is often tasked with ensuring equal justice under law.

In many jurisdictions the judicial branch has the power to change laws through the process of judicial review. Courts with judicial review power may annul the laws and rules of the state when it finds them incompatible with a higher norm, such as primary legislation, the provisions of the constitution or international law.