The is a driver for the PCI Express (PCIe) controller on motherboards with Intel 8th-generation (Coffee Lake) processors. PCIe is the interface through which your computer communicates with peripherals like graphics cards, storage devices, and other expansion cards.

The 3E81 in this case is an identifier for a specific version or model of the Intel PCIe controller, which is crucial for ensuring that the communication between the processor and the devices connected through PCIe slots (like GPUs or SSDs) works properly.