Police are law enforcement officers who are responsible for maintaining public order, enforcing the law, and other related activities. They are often tasked with various licensing and regulatory functions as well, but their primary role is to protect life and property by apprehending criminals and reporting on them to the courts. The precise functions of police forces vary between countries. Generally, they are organized as a hierarchical body with multiple ranks and are accountable to a civilian oversight body.
There are a number of factors that contribute to the diversity of police systems, including the types of crimes committed, the methods used by criminals, and the country’s political culture. The desire for efficiency lends itself to the establishment of centralized police forces, which can take advantage of economies of scale and coordination, but they must face the thorny question aptly expressed in Latin: “quis custodiet ipsos custodes?”
Another factor is the size of the force; policing rural areas and small towns requires different skills and tools than policing large cities, and even within a single city, policing districts differ. Many modern police forces use two-way radio communications equipment, carried on the person or installed in vehicles, to coordinate their operations and respond to calls quickly and efficiently. They also use portable and vehicle-installed mobile data terminals to enter information, conduct criminal background checks on persons of interest, and update their daily activity logs and other required reports, all in real time.