【中文版】

银行卡校验码（CVV码）是银行卡密码的一种形式，主要用于网上银行和电话银行等非面对面交易的验证。CVV码通常由卡号、有效期和验证码三部分组成，每张银行卡的验证码都是独一无二的。在非面对面交易中，除了提供卡号和有效期外，还需要提供CVV码，以确保交易的安全性。

CVV码的生成方式通常是由银行根据一定的算法和规则对卡号等信息进行加密得到的。由于每张银行卡的验证码都是不同的，因此使用CVV码进行交易验证可以大大提高安全性。

在使用CVV码进行交易时，需要注意以下几点：首先，不要将CVV码和银行卡密码混淆，CVV码是用于非面对面交易的验证，而银行卡密码通常用于ATM机等面对面交易的验证；其次，在使用CVV码进行交易时，需要确保网站或应用程序的合法性和安全性，以避免遭受欺诈攻击；最后，如果发现自己的CVV码被他人获取或盗用，需要及时联系银行进行处理。

总之，银行卡校验码是保障非面对面交易安全的重要措施之一，在使用时需要注意保护好自己的个人信息和账户安全。

【英文版】

Bank card verification code (CVV code) is a type of bank card password used mainly for verification in online banking and telephone banking. The CVV code usually consists of card number, expiration date, and verification code, and each bank card's verification code is unique. In non-face-to-face transactions, in addition to providing the card number and expiration date, the CVV code is also required to ensure the security of the transaction.

The generation method of CVV code is usually obtained by encrypting card information with a certain algorithm and rule by the bank. Since each bank card's verification code is different, using CVV code for transaction verification can greatly improve security.

When using CVV code for transactions, the following points need to be noted: firstly, do not confuse CVV code with the bank card password, which is usually used for ATM machine and face-to-face transactions; secondly, when using CVV code for transactions, we need to ensure the legitimacy and security of the website or application to avoid fraud attacks; lastly, if your CVV code is obtained or stolen by others, you need to contact your bank in a timely manner for processing.

In summary, the bank card verification code is one of the important measures to ensure the security of non-face-to-face transactions. When using it, we need to pay attention to protecting your personal information and account security.