The Broadcom 802.11ac WDI SDIO Adapter is a wireless network driver used for managing Wi-Fi connectivity on Windows devices. It supports the 802.11ac wireless standard, which provides faster speeds and better performance than older standards like 802.11n. This driver is specifically for Broadcom wireless network cards or chipsets that communicate with the system using the SDIO (Secure Digital Input/Output) interface.

The "WDI" part of the name stands for Windows Driver Framework (WDF) for Wi-Fi Direct. Wi-Fi Direct allows devices to connect directly to each other without needing a wireless access point (router), which is part of the overall functionality this driver enables.