A USB Card Reader/Writer is a device that allows you to read and write data to various types of memory cards (such as SD, microSD, CF cards, etc.) through a USB port on your computer. These devices are commonly used to transfer data between memory cards (used in cameras, smartphones, and other devices) and a computer.
The USB Card Reader/Writer Windows driver is a software component that allows your Windows operating system to recognize and communicate with the card reader hardware. Without the driver, the computer may not recognize the card reader, or it may not function properly (e.g., no data transfer or card access issues).