Standalone access means there is no connections between doors, each door needs to be set up individually. Access with either numeric keypad or card. Example Schlage NDE locks can be on a WiFi network and managed remotely, however the door still a standalone.
CARD OR FOB ACCESS
Card Access system, all doors connected together, managed by software locally, or remotely if internet is available. The system is allow to have different access levels, schedules, review and print event history. For added security, card readers with a built in keypad requires to present a card and enter a code in the same time.
The next level is to use biometrics, fingerprint or retina scanners for high security applications.
Phone Entry Systems in multi tenant buildings allows to the visitor call up the resident phone who wish to visit to gain access to the building or open a gate.