smart card fundamentals

The official definition of smart card is “an integrated circuit card with memory capable of making decisions.” It is therefore not a magnetic stripe card, like the typical US credit card, that has a capacity of 300 bytes of non-rewriteable memory and no processing capability. It is not a memory card, like some devices of the size of a credit card able to store a few megabytes of data using optical technology. However, it is also not a PC card ­p; also known as PCMCIA ­p; which can be much more intelligent and have more memory, but is much thicker and rigid, requires a very delicate connection based on a couple dozen pins, and costs at least ten times as much as a smart card.
Smart cards differ along four main dimensions:
Memory: from 1 to 16 kb (there are currently prototypes with 64 kb);
Processor speed: from 4 to 16 MHz;
Interaction: physical contact, proximity (near-contact, but no wearout), and radio;
Software: card operating system and installed applications.