How can the machine know the informationof your account ??

are you from hong knog ?
well anyway since yo ask in english, won't hesitate to use them.
well ,at the back of your card there is amgnetic strip and i assum that is ATM auto teller machine/
they are called terminals in newtworking ,they are connected to the server,
all the data are store in the server and when you put you card in then it will get and verify record thats it ...
anymore question :-p
feel free te email me