Card Readers, also known as Card Entry Systems, have traditionally come in two forms, a "Card Swipe" which utilizes a magnetic strip, similar to a credit card and a Proximity Card more commonly known as "Prox Card," which uses RFID Technology (Radio Frequency Identification). The Card Entry Systems use their respective cards as "Key Cards" to control idividual access to areas within a facility or office.

Card Swipe Systems, though still used by some Companies and Universities, are quickly being replaced with Proximity Card Reader Systems or “Prox cards.” This technology is ideal for controlling access as well as maintaining an audit trail of who comes and goes.

The Proximity Card Reader systems uses cards with RFID chips in them that the readers sense when the card comes into range. This Proximity Card Reader Systems is ideal because the prox cards do not ware out like magnetic strip on the standard card swipe. Proximity Card Readers also last longer because there are no moving parts that wear out or contacts that get dirty.