Letter of Credit (L/C) refers to a letter of credit issued by a bank (issuing bank) in accordance with the requirements and instructions of the (applicant) or on its own initiative and in compliance with the terms of the letter of credit. A written document that stipulates the payment of documents to a third party (the beneficiary) or his designee. That is, a letter of credit is a written document issued by a bank with a conditional commitment to pay. In international trade activities, buyers and sellers may not trust each other. The buyer is worried that the seller will not deliver goods as required in the contract after making advance payment; the seller is also worried that the buyer will not pay after shipping or submitting shipping documents. Therefore, two banks are needed as guarantors for both the buyer and the seller, to collect and deliver documents on their behalf, and to replace commercial credit with bank credit. The instrument used by banks in this activity is the letter of credit. A credit card is a special carrier card issued by commercial banks to individuals and organizations, which allows them to shop and consume with special entities and deposit and withdraw cash from banks. It is a special carrier card with consumer credit. It is in the form of a card with the name, validity period, number, and number of the issuing bank printed on the front. Cards containing the cardholder's name, etc., and a magnetic stripe and signature strip on the back. What we call credit cards now generally refers to credit cards only. In layman's terms, a credit card is a small loan payment tool provided by banks to users who consume first and repay later. That is, when your shopping needs exceed your ability to pay or you do not want to use cash, you can borrow money from the bank. This kind of borrowing does not require any interest or handling fees. A credit card is a certificate that a bank promises to lend you money. A credit card will tell you how much money you can borrow from the bank and when you need to pay it back. In addition, you can also withdraw cash directly from the ATM machine when there is no money in your credit card.