Card processing refers to the system that enables businesses to accept payments made through credit or debit cards. When a customer makes a purchase, their card information is securely transmitted to a payment processor, which verifies the transaction with the card issuer, such as a bank. This process ensures that the funds are available and that the transaction is legitimate. Once the transaction is approved, the payment processor facilitates the transfer of funds from the customer's account to the merchant's account. This entire process typically takes just a few seconds, allowing for quick and efficient transactions in various settings, including online shopping and in-store purchases.