Contact Cards

Cards the size of a conventional credit or debit card with a single
embedded integrated circuit chip that contains just memory or
memory plus a microprocessor. 

Popular Uses: Network security, vending, meal plans, loyalty,
electronic cash, government IDs, campus IDs, e-commerce, health card.

Contactless Cards

Cards containing an embedded antenna instead of contact pads
attached to the chip for reading and writing information contained
in the chip's memory.  

Popular Uses: Student identification, electronic passport, vending,
parking, tolls, IDs.

Proximity Cards

Prox Cards communicate through an antenna similar to
contactless smart cards except that they are read-only.  

Popular Uses:  Security, identification, access control

Hybrid / Twin Cards

Cards containing two or more embedded chip technologies
such as a prox chip with its antenna and a contact smart chip
with its contact pads.

Popular Uses: Accommodates legacy system infrastructure while
adding applications that require different e-card technologies.

Combi Cards

Cards containing one smart chip that can be accessed through
either contact pads or an embedded antenna.

Popular Uses: Mass transit and access control combined with other
applications such as network security, vending, meal plans, loyalty, etc.