Smart card. Close-up of a vodafone smart card or memory card. Smart cards are used to store information electronically. Similar in size to a credit card, they contain information on an in- built microprocessor chip. Smart cards can contain a central processing unit which can store, secure and act on information, that can be added or erased as required. Alternatively, the card may just be used to store fixed information, such as an employee's personal details. The chip protects the stored information from damage or theft, making a smart card much more secure than a magnetic stripe card, which carries information on its outside where it can be easily copied.