Isn't it mostly obvious? Offline transactions are needed whenever a transaction is made without access to the internet. Like a train in the middle of nowhere or

Isn't it mostly obvious? Offline transactions are needed whenever a transaction is made without access to the internet. Like a train in the middle of nowhere or a flight. Typically the POS just accepts the card, and then when Internet access is restored, sends them all out. So the merchant takes the risk of a customer using a bad card. But with smart functionality in the card, the card itself could make a determination of whether the payment should be approved.