La polizia è costituita da un corpo di persone abilitate dallo stato a far rispettare la legge

The police are a constituted body of persons empowered by a state, to enforce the law, ensure the safety, health, and possessions of citizens, and prevent crime and civil disorder. Their lawful powers include arrest and the use of force legitimized by the state via the monopoly on violence. The term is most commonly associated with the police forces of a sovereign state that are authorized to exercise the police power of that state within a defined legal or territorial area of responsibility. Police forces are often defined as being separate from the military and other organizations involved in the defense of the state against foreign aggressors; however, the gendarmerie is a military unit charged with civil policing. Police forces are usually public sector services, funded through taxes.

Law enforcement is 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. In some societies, in the late 18th and early 19th centuries, these developed within the context of maintaining the class system and the protection of private property. Police forces have become ubiquitous in modern societies. Nevertheless, their role can be controversial, as they may be involved to varying degrees in corruption, brutality, and the enforcement of authoritarian rule.

A police force may also be referred to as a police department, police service, constabulary, gendarmerie, crime prevention, protective services, law enforcement agency, civil guard, or civic guard. Members may be referred to as police officers, troopers, sheriffs, constables, rangers, peace officers, or civic/civil guards. Ireland differs from other English-speaking countries by using the Irish language terms Garda (singular) and Gardaí (plural), for both the national police force and its members. The word police are the most universal and similar terms can be seen in many non-English speaking countries.

Numerous slang terms exist for the police. Many slang terms for police officers are decades or centuries old with lost etymologies. One of the oldest, cop, has largely lost its slang connotations and become a common colloquial term used both by the public and police officers to refer to their profession.

Law enforcement systems existed in the various kingdoms and empires of ancient India. The Apastamba Dharmasutra prescribes that kings should appoint officers and subordinates in the towns and villages to protect their subjects from crime. Various inscriptions and literature from ancient India suggest that a variety of roles existed for law enforcement officials such as those of a constable, thief catcher, watchman, and detective. In ancient India up to medieval and early modern times, kotwals were in charge of local law enforcement.

In India, the police are under the control of respective States and union territories and are known to be under State Police Services (SPS). The candidates selected for the SPS are usually posted as Deputy Superintendent of Police or Assistant Commissioner of Police once their probationary period ends. On prescribed satisfactory service in the SPS, the officers are nominated to the Indian Police Service. The service color is usually dark blue and red, while the uniform color is Khaki.

Michel Foucault wrote that the contemporary concept of police as a paid and funded functionary of the state was developed by German and French legal scholars and practitioners in public administration and statistics in the 17th and early 18th centuries, most notably with Nicolas Delamare's Traité de la Police ("Treatise on the Police"), first published in 1705. The German Polizeiwissenschaft (Science of Police) was first theorized by Philipp von Hörnigk, a 17th-century Austrian political economist and civil servant.