Why do the Italians have so many different kinds. They often come under the general term of "vigili" and they include the vigili urbani, (ordinary town bobbies) and the carabinieri, who are said to be more military and who often carry arms.
There has recently been a move to arm the urban bobbies but Il Piccolo says that the Triestini are in general strongly opposed to the idea.
The notes in my copies of Andrea Camilleri's books about Commissario (Inspector) Montalbano say the Commissariat comprises yet another kind of bobby who conduct "indagini", investigations. Montalbano is sometimes addressed as "dottore" who simply seems to mean that he has been to university and may not hold a doctorate.
Firemen (don't tell me; I know they're persons) and customs persons are also referred to as "vigili".
It is the same in English. Vigilante = vigilant, watchful, watchman,guard, caretaker.
vigilanza = vigilance, care, check, control. Commissione di vigilanza = supervisory committe,
Vigilare = to supervise, to keep a watch (eye, check) on.
Vigilato = watched, guarded, under supervision.
Vigile = watchful, vigilant, alert.
Vigilia = eve, night(or day) before, giorno di vigilia = a day of abstinance.
BUT, be careful how you spell it. Vigliacco means thief or coward.