Police
Police are organizations operated by the state whose primary purpose is to protect the ruling class and their continued rule, through the means of whatever violence on their part is “necessary”. They are either always armed, or occasionally (in a few countries) unarmed, but who can quickly become armed if need arises. They may have, on occasion, other auxiliary duties, such as traffic control, but by far their most important and central purpose is to protect the rule of one social class or another.
Under capitalism, this means that their primary and most essential task is to safeguard the rich, their property, and their exploitative system of capitalist class rule. Capitalist police also function as strike-breakers, evictors of the homeless, and agents of state terrorism.