What is a "private security services business"?

Any person engaged in the business of providing, or who undertakes to provide, armored car personnel, security officers, personal protection specialists, private investigators, couriers, security canine handlers, security canine teams, detector canine handlers, detector canine teams, alarm respondents, locksmiths, central station dispatchers, electronic security employees, electronic security sales representatives or electronic security technicians and their assistants to another person under contract, expressed or implied.