The Acer Composite USB Device is a Windows driver used for various Acer devices, typically for those that feature USB connectivity. These devices may include smartphones, tablets, or other devices that use a USB connection for transferring data or performing functions like charging, synchronization, or debugging. The term "composite" refers to the fact that this device might combine multiple functions over a single USB connection, such as ADB (Android Debug Bridge) and MTP (Media Transfer Protocol), allowing the device to serve both as a storage device and for other functionalities like debugging or tethering.

For instance, an Acer Android smartphone or tablet might use this driver for connecting to a Windows PC, allowing it to perform various functions like file transfers, charging, or communication for development purposes.