Police in the context of Accuracy International Arctic Warfare

Law enforcement is the activity of some members of the government or other social institutions who act in an organized manner to enforce the law by investigating, deterring, rehabilitating, or punishing people who violate the rules and norms governing that society. The term encompasses police, courts and corrections. These three components of the criminal justice system may operate independently of each other or collectively through the use of record sharing and cooperation. Throughout the world, law enforcement are also associated with protecting the public, life, property, and keeping the peace in society.

The concept of law enforcement dates back to ancient times, and forms of law enforcement and police have existed in various forms across many human societies. Modern state legal codes use the term law enforcement officer or peace officer to include every person vested by the legislating state with police power or authority; traditionally, anyone sworn or badged who can arrest any person for a violation of criminal law is included under the umbrella term of law enforcement.

A public service or service of general (economic) interest is any service intended to address the needs of aggregate members of a community, whether provided directly by a public sector agency, via public financing available to private businesses or voluntary organisations, or by private businesses subject to government regulation. Some public services are provided on behalf of a government's residents or in the interest of its citizens. The term is associated with a social consensus (usually expressed through democratic elections) that certain services should be available to all, regardless of income, physical ability or mental acuity. Examples of such services include the fire services, police, air force, paramedics and public service broadcasting.

Even where public services are neither publicly provided nor publicly financed, they are usually subject to regulation beyond that applying to most economic sectors for social and political reasons. Public policy, when made in the public's interest and with its motivations, is a type of public service.

The Police (Polish: Policja, [pɔˈlit͡sja] ) is the national civilian police service of Poland. It is the country’s primary law enforcement agency, responsible for public security and order as well as the prevention and investigation of crime. It operates under the authority of the Ministry of the Interior and Administration.

Polish Police is headed by the Commander-in-Chief of Police, subordinate to the Minister of the Interior and Administration. The Police is supported by municipal forces of city guards, having less legal authority and with jurisdiction only over prosecuting contraventions.

A law enforcement agency (LEA) is any government agency responsible for law enforcement within a specific jurisdiction through the employment and deployment of law enforcement officers and their resources. The most common type of law enforcement agency is the police, but various other forms exist as well, including agencies that focus on specific legal violation, or are organized and overseen by certain authorities. They typically have various powers and legal rights to allow them to perform their duties, such as the power of arrest and the use of force.

Protest policing or public order policing is part of a state’s response to political dissent and social movements. Police maintenance of public order during protest is an essential component of liberal democracy, with military response to protest being more common under authoritarian regimes.

Australasian, European, and North American democratic states have all experienced increased surveillance of protest movements and more militarized protest policing since 1995 and through the first decades of the 21st century.

An arrest is the act of apprehending and taking a person into custody (legal protection or control), usually because the person has been suspected of or observed committing a crime. After being taken into custody, the person can be questioned further or charged. An arrest is a procedure in a criminal justice system, sometimes it is also done after a court warrant for the arrest.

Police and various other officers have powers of arrest. In some places, a citizen's arrest is permitted; for example in England and Wales, any person can arrest "anyone whom he has reasonable grounds for suspecting to be committing, have committed or be guilty of committing an indictable offence", although certain conditions must be met before taking such action. Similar powers exist in France, Italy, Germany, Austria and Switzerland if a person is caught in an act of crime and not willing or able to produce valid ID.

A police state is a state whose government institutions exercise an extreme level of control over civil society and liberties. There is typically little to no distinction between the law and the exercise of political power by the executive, and the deployment of internal security and police forces play a heightened role in governance. A police state is a characteristic of authoritarian, totalitarian or illiberal regimes (contrary to a liberal democratic regime). Such governments are not exclusive to simply one-party states or dominant-party states, as they can also arise in a democracy or multi-party system.

Originally, a police state was a state regulated by a civil administration, but since the beginning of the 20th century it has "taken on an emotional and derogatory meaning" by describing an undesirable state of living characterized by the overbearing presence of civil authorities. The inhabitants of a police state may experience restrictions on their mobility, or on their freedom to express or communicate political or other views, which are subject to police monitoring or enforcement. Political control may be exerted by means of a secret police force that operates outside the boundaries normally imposed by a constitutional state. Robert von Mohl, who first introduced the rule of law to German jurisprudence, contrasted the Rechtsstaat ("legal" or "constitutional" state) with the anti-aristocratic Polizeistaat ("police state").

Riot police are police who are organized, deployed, trained or equipped to confront crowds, protests or riots.

Riot police may be regular police officers who act in the role of riot police in particular situations, or they may be separate units organized within or in parallel to regular police forces. Riot police are used in a variety of different situations and purposes. They may be employed to control riots as their name suggests, to disperse or control crowds, to maintain public order or discourage criminality, or to protect people or property. The militarization of modern police has brought militaristic riot gear and new technologies that allow for their duties to expand above normal police duties.

Criminal investigation is an applied science that involves the study of facts that are then used to inform criminal trials. A complete criminal investigation can include searching, interviews, interrogations, evidence collection and preservation, and various methods of investigation. Modern-day criminal investigations commonly employ many modern scientific techniques known collectively as forensic science.

Criminal investigation is an ancient science that may have roots as far back as c. 1700 BCE in the writings of the Code of Hammurabi. In the code, it is suggested that both the accuser and the accused had the right to present evidence they collected. In the modern era, criminals investigations are most often done by government police forces. Private investigators are also commonly hired to complete or assist in criminal investigations.

Conscription, also known as the draft in American English, is the practice in which the compulsory enlistment in a national service, mainly a military service, is enforced by law. Conscription dates back to antiquity and it continues in some countries to the present day under various names. The modern system of near-universal national conscription for young men dates to the French Revolution in the 1790s, where it became the basis of a very large and powerful military. Most European nations later copied the system in peacetime, so that men at a certain age would serve 1 to 8 years on active duty and then transfer to the reserve force. In the early 2000, Norway and Sweden became the first nations to conscript women on the same legal terms as men. Denmark has committed to implement a similar system shortly.

Conscription is controversial for a range of reasons, including conscientious objection to military engagements on religious or philosophical grounds; political objection, for example to service for a disliked government or unpopular war; sexism, in that historically only men have been subject to the draft; and ideological objection, for example, to a perceived violation of individual rights. Those conscripted may evade service, sometimes by leaving the country, and seeking asylum in another country. Some selection systems accommodate these attitudes by providing alternative service outside combat-operations roles or even outside the military, such as siviilipalvelus (alternative civil service) in Finland and Zivildienst (compulsory community service) in Austria and Switzerland. Several countries conscript male soldiers not only for armed forces, but also for paramilitary agencies, which are dedicated to police-like domestic-only service like internal troops, border guards or non-combat rescue duties like civil defence.

Secret police (or political police) are police, intelligence or security agencies that engage in covert operations against a government's political, ideological or social opponents and dissidents. Secret police organizations are characteristic of authoritarian and totalitarian regimes. They protect the political power of a dictator or regime and often operate outside the law to repress dissidents and weaken political opposition, frequently using violence. They may enjoy legal sanction to hold and charge suspects without ever identifying their organization.

Public capital is the aggregate body of government-owned assets that are used as a means for productivity. Such assets span a wide range including: large components such as highways, airports, roads, transit systems, and railways; local, municipal components such as public education, public hospitals, police and fire protection, prisons, and courts; and critical components including water and sewer systems, public electric and gas utilities, and telecommunications. Often, public capital is defined as government outlay, in terms of money, and as physical stock, in terms of infrastructure.

Guerrilla warfare is a type of unconventional warfare in which small groups of irregular military, such as rebels, partisans, paramilitary personnel or armed civilians, which may include children in the military, use ambushes, sabotage, terrorism, raids, petty warfare or hit-and-run tactics in a rebellion, in a violent conflict, in a war or in a civil war to fight against regular military, police or rival insurgent forces.

Although the term "guerrilla warfare" was coined in the context of the Peninsular War in the 19th century, the tactical methods of guerrilla warfare have long been in use. In the 6th century BC, Sun Tzu proposed the use of guerrilla-style tactics in The Art of War. The 3rd century BC Roman general Quintus Fabius Maximus Verrucosus is also credited with inventing many of the tactics of guerrilla warfare through what is today called the Fabian strategy, and in China Peng Yue is also often regarded as the inventor of guerrilla warfare. Guerrilla warfare has been used by various factions throughout history and is particularly associated with revolutionary movements and popular resistance against invading or occupying armies.

A commissioner (commonly abbreviated as Comm'r) is, in principle, a member of a commission or an individual who has been given a commission (official charge or authority to do something).

In practice, the title of commissioner has evolved to include a variety of senior officials, often sitting on a specific commission. In particular, the commissioner frequently refers to senior police or government officials. A high commissioner is equivalent to an ambassador, originally between the United Kingdom and the Dominions and now between all Commonwealth states, whether Commonwealth realms, republics or countries having a monarch other than that of the realms. The title is sometimes given to senior officials in the private sector; for instance, many North American sports leagues.

Civil authority or civil government is the practical implementation of a state on behalf of its citizens, other than through military units (martial law), that enforces law and order and that is distinguished from religious authority (for example, canon law) and secular authority. The enforcement of law and order is typically the role of the police in modern states.

Military ranks are a system of hierarchical relationships within armed forces, police, intelligence agencies and other institutions organized along military lines. Responsibility for personnel, equipment and missions grows with each advancement. The military rank system defines dominance, authority and responsibility within a military hierarchy. It incorporates the principles of exercising power and authority into the military chain of command—the succession of commanders superior to subordinates through which command is exercised. The military chain of command is an important component for organized collective action.

Uniforms denote the bearer's rank by particular insignia affixed to the uniforms of a number of countries. Ranking systems have been known for most of military history to be advantageous for military operations, in particular with regards to logistics, command, and coordination. As time went on and military operations became larger and more complex, more ranks were created and the systems of ranking became more complex.

In criminal justice, particularly in North America, correction, corrections, and correctional, are umbrella terms describing a variety of functions typically carried out by government agencies, and involving the punishment, treatment, and supervision of persons who have been convicted of crimes. These functions commonly include imprisonment, parole, and probation. A typical correctional institution is a prison. A correctional system, also known as a penal system, thus refers to a network of agencies that administer a jurisdiction's prisons, and community-based programs like parole, and probation boards. This system is part of the larger criminal justice system, which additionally includes police, prosecution and courts.

"Corrections" is also the name of a field of academic study concerned with the theories, policies, and programs pertaining to the practice of corrections. Its object of study includes personnel training and management as well as the experiences of those on the other side of the fence — the unwilling subjects of the correctional process. Stohr and colleagues (2008) write that "Earlier scholars were more honest, calling what we now call corrections by the name penology, which means the study of punishment for crime."

In France, a Prefecture of Police (French: Préfecture de police), headed by the Prefect of Police (Préfet de police), is an agency of the Government of France under the administration of the Ministry of the Interior. Part of the National Police, it provides a police force for an area limited by department borders. As of 2012, two such prefectures exist:

• The Paris Police Prefecture, created in 1800
• The Bouches-du-Rhône Police Prefecture, created in 2012