Smart card can be generally devided into contact smart card and contactless smart card. The contact smart card have a copper interface pad embedded on the surface of the card. The card must be inserted into a smart card reader to make a direct connection for the transfer of data. Contactless smart cards only require close proximity to a reader (usually within a few inches) to achieve data transmission. Contact smart cards typically have more memory and processing power than contactless cards. Some data encryption processes (used in high-security financial or legal applications) can only be performed by contact smart cards.