Proximity Cards are identification cards which contain information that can be detected by readers placed in proximity to them.

Embedded in each proximity card is an antenna which transmits information encoded as a radio signal. (Anther name for ID badges of this kind is "Radio Frequency Identification", or RFID cards.) A proximity card reader positioned between 2.5 and 20 inches (depending on the model chosen) receives this signal and grants or denies access accordingly. Unlike contactless smart cards, proximity cards do not have the ability to have new information written onto them.

Many organizations need to restrict entry into particular places within their facilities. Proximity cards provide ID card security while allowing fast, easy access to areas an organization otherwise proscribes.

Proximity cards often work together with ID card software. Information of the person who has been distributed this ID card, stored on a microchip and transmitted in a radio wave, appears on a computer screen to verify the cardholder's identity. The entrances and exits of the proximity card holder can then be logged into a computer database, providing a digital record of who was in a given area at any given time.