First off, what is a credit card? A credit card is a card issued by a bank, retailer or consumer store, which lets you buy goods and services on credit for a specific limit, interest rate and time period. There are many types of credit cards to choose from, all depending on the needs of the holder.. You can apply for a credit card online, through paper application or by phone. Applying for a credit card is easy, and before this post is over you’ll understand.