中文版：

信用卡二卡是什么意思？

信用卡二卡是银行推出的信用卡主卡及副卡。副卡是相对于主卡而言的，主卡持卡人可自行设置副卡的额度，也可选择禁止使用副卡。当主卡持卡人选择最低还款的时候，副卡所有的消费都需要计入主卡的最低还款金额。副卡主要目的是给持卡人提供额外的支付渠道。

在使用过程中，主卡和副卡必须是同一人名下，称“共用”帐户。一张主卡最多可以申请两张副卡，且副卡可以设密码，不设密码的副卡必须去主卡开户网点激活后才可以使用。

总的来说，信用卡二卡是银行推出的一种方便持卡人使用的信用卡服务。

英文版：

What is the second card of credit card?

The second card of credit card is the main card and the supplementary card launched by the bank. The supplementary card is relative to the main card, and the main cardholder can set the credit limit of the supplementary card or choose to prohibit its use. When the main cardholder chooses the minimum repayment, all expenses of the supplementary card should be included in the minimum repayment amount of the main card. The main purpose of the supplementary card is to provide the cardholder with additional payment channels.

In the process of use, the main card and the supplementary card must be in the same person's name, known as a "shared" account. One main card can apply for up to two supplementary cards, and each supplementary card can be set with a password. The supplementary card without password must be activated at the main card account opening branch before it can be used.

In general, the second card of credit card is a convenient service for cardholders launched by the bank.