Police

A police force is a constituted body of persons empowered by the state to enforce the law, protect property and limit civil disorder. Their powers include the legitimized use force, with this term being most commonly associated with police services of a sovereign state that are authorized to exercise the police power of that state within a defined legal or territorial area of responsibility. Law enforcement, however, constitutes only part of policing activity. Policing has included an array of activities in different situations, but the predominant ones are concerned with the preservation of order.

Uniformed Police
Preventive Police, also called Uniformed Branch, Uniformed Police, Uniform Divison, Order Police, Administrative Police or Patrol, designates the police that patrol and respond to emergencies and other incidents as opposed to detective services. They wear uniforms and perform functions that require an immediant recognition of an officer's legal authority such as traffic control, stopping and detaining motorists and more active crime response and prevention. They make up the backbone of police service's personnel.

Detectives
Police detectives are responsible for investigations and detective work, also known as Investigations Police, Judiciary/Judical Police or Criminal Police. Detectives typically wear "business attire" in bureaucratic and investigative functions where a uniformed presence would be either a distraction or intimidating, but a need to establish police authority still exists. "Plainclothes" officers dress in attire consistent with that worn by the general public for purposes of blending in.

In some cases, police are assigned to work undercover, where they conceal their police identity to investigate crimes such as organized crime or narcotics crime, that are unsolvable by other means. In some cases this type of policing shares aspects with espionage.

Auxillary
Police may also take on auxillary administrative duties such as issuing firearm licenses. The extent that police have these functions varies among countries, with police in France, Germany and other continental European countries handling such tasks to a greater extent than British counterparts.

Specialized Units
Specialized preventive and detective groups or Specialist Investigation Departments exist within many law enforcement organizations either for dealing with particular types of crime such as traffic law enforcement and crash investigation, homicide or fraud; or for situations requiring specialized skills such as underwater search, aviation, explosive device disposal (bomb squad) and computer crime.

Most larger jurisdictions also employ specially selected and trained quasi-military units armed with military-grade weapons for the purposes of dealing with particularly violent situations beyond the capability of a patrol officer response including high-risk warrant service and barricaded suspects. In the United States these units go by a variety of names, but are commonly known as SWAT teams.

In counterinsurgency-type campaigns, select and specially trained units of police armed and equipped as light infantry have been designated as police field forces who perform paramilitary-type patrols and ambushes whilst retaining their police powers in areas that were highly dangerous. Because of their situational mandate typically focuses on removing innocent bystanders from dangerous people and dangerous situations, not violent resolution, they are often equipped with non-lethal tactical tools like chemical agents, flashbang and concussion grenades and rubber bellets. The London Metropolitian police's Specialist Firearms Command (CO19) is a group of armed police used in dangerous situations including hostage taking, armed robbery/assault and terrorism.

Military Police
Military police could be:
 * A section of the military solely responsible for policing the armed forces, referred to as provosts.
 * A section of the military responsible for policing in both the armed forces and in the civilian population like most gendarmeries such as the French Gendarmerie, the Italian Carabineiri, the Spanish Guardia Civil and the Portuguese Republician National Guard.
 * A section of the military solely responsible for policing the civilian population like the Romanian Gendarmerie.
 * The civilian preventive police of a Brazillian state like the Policia Militar.
 * A special military law enforcement service like the Russian Military Police.

Religious Police
Some Islamic societies have religious police, who enforce the application of Islamic Sharia law. Their authority may include the power to arrest unrelated men and women caught socializing, anyone engaged in homosexual behavior or prostitution; to enforce Islamic dress codes and store closures during Islamic prayer time.

Weapons
In many jurisdictions, police officers carry firearms, primarily handguns, in the normal course of their duties. Police often have specialist units for handling armed offenders and similar dangerous situations, and can, in some extreme circumstances, call on the military. They can also be armed with non-lethal weaponry, particularly for riot control. These include batons, tear gas, riot control agents, rubber bullets, riot shields, water cannons and electroshock weapons. Police officers often carry handcuffs to restrain suspects too. The use of firearms or deadly force is typically a last resort only to be used when necessary to save human life, although some jurisdictions allow it's use against fleeing felons and escaped convicts. A "shoot to kill" policy was recently introduced in South Africa, which allows police to use deadly force against any person who poses a significant threat to them or civilians.

Communications
Modern police make extensive use of radio communications equipment, carried both on the person and installed in vehicles to coordinate their work, share information and get help quickly. In recent years, vehicle-installed computers have enhanced the ability of police communications, enabling easier dispatching of calls, criminal background checks on persons of interest to be completed in a matter of seconds and updating officers' daily activity log and other, required reports on a real-time basis. Other common pieces of police equipment include flashlights/torches, whistles, police notebooks and ticket books or citations.