A credit card reader is a device that allows businesses to accept payments made with credit or debit cards. It works by reading the information stored on the card's magnetic stripe or chip, enabling secure transactions. These devices can be standalone or integrated into point-of-sale systems, making it easier for customers to pay for goods and services. Many credit card readers connect to smartphones or tablets via Bluetooth or a headphone jack, allowing for mobile payments. They are commonly used in retail stores, restaurants, and at events, providing a convenient way for customers to complete their purchases without cash.