Mike. The ESC comes usually plug`n`play, but there are several parameters you can set yourself…such as nimh/Lipo battery type, voltage, cutoff voltage and so on.
The ESC will buzz the motor and make bleeping nosies, and by various combinations of bleeps and moving the stick up and down, can set these using the transmitter. This is however jolly confusing.
A programming card enables you to power the esc up with a battery and plug in the card, and set these parameters very easily by using buttons oe switches on the card (caries from type to type.
The JP-Pro ESC card is the easiest I have seen, as the parameters are pre set by moving links on the side of the card, and once done you simply plug the esc in, power up..and thats it. (these are aircraft style esc I have used on the ecranoplans)
Program cards are very cheap and you really do not want to buy a brushless ESC without one.
Ashley