Neighborhood Watch is a program that may exist in some communities, in which community members agree to “keep watch” in their neighborhood and report anything they deem to be suspicious to police. They are a part of community policing, in which police encourage community members to act as extensions of the police in their own neighborhoods.
Members of a neighborhood watch typically have regular meetings with police and receive regular updates from police regarding crime reports and alerts in their neighborhood.
Neighborhood Watch areas may indicate they are such by posting signs and/or flyers.
Image description: A red, white, and black street sign reads “WARNING / NEIGHBORHOOD WATCH / CITY OF LOS ANGELES L.A.P.D.” Image source: ecprops.com