The D-Link DUB-E100 USB 2.0 to Fast Ethernet Adapter is a device that allows you to add a Fast Ethernet (10/100 Mbps) network connection to your computer or laptop through a USB 2.0 port. This adapter is particularly useful for devices that do not have a built-in Ethernet port (e.g., many ultrabooks or laptops) or when you need an additional network interface for your system.

The D-Link DUB-E100 driver is the software required to allow your computer to properly communicate with and use the DUB-E100 USB-to-Ethernet adapter. Without this driver, the operating system won't recognize the device and won't be able to use it for network connections.