A contactless smart card is in any pocket-sized card with embedded integrated circuits which can process and store data. This implies that it can receive input which is processed and delivered as an output via radio frequencies. There are two broad categories of contactless smart cards. Memory cards contain non-volatile memory storage components, and perhaps some specific security logic. Contrary to popular belief contactless smart cards do not contain an ordinary read-only RFID, but they do contain a re-writable smart card microchip that can be transcribed via radio frequencies.