The Quectel USB AT Port Windows driver is a software package that enables communication between a Quectel cellular module (like a 4G LTE or 5G modem) and your Windows computer via a USB connection. This driver allows you to send AT commands to the module, which is typically used for tasks such as setting up network connections, sending SMS, or managing cellular data modules.

Quectel modules often use AT commands for controlling and configuring the device, and the USB AT Port driver is needed for Windows to recognize and properly interface with the module via USB.