Data cards may be classified by their functions:

• Expansion cards or printed-circuit boards: Used in video cards, sound cards and network cards
• Memory cards: Used in cameras, MP3 players, dictaphones, hand-held computer, smart phones and mobile phones, etc.
• Identification cards: Used for telecom, prepaid services, banking and security
• Electronic cards: Constructed in relation to geographical information systems

Data cards feature time tracking through identification systems. They are made of plastic (polyvinyl chloride, acrylonitrile butadiene styrene or polycarbonate) and located in flash memory modules and memory sticks, also known as USB drives, facilitating temporary backup, portability and easy access.