wpa_supplicant is a free software implementation of an IEEE 802.11i supplicant for Linux, FreeBSD, NetBSD, QNX, AROS, Microsoft Windows, Solaris, OS/2 (including ArcaOS and eComStation) and Haiku. In addition to being a WPA3 and WPA2 supplicant, it also implements WPA and older wireless LAN security protocols.

Is wpa_supplicant required?

Wireless network interface configuration requires a backend, generally wpa_supplicant (often in conjunction with ifupdown and other utilities) or IWD. These can be used with connection managers that provide advanced functionality, and an easier way to configure them.

What is wpa_supplicant SME?

wpa_supplicant is a userspace application which works as a WPA supplicant and SME (to handle initiating MLME commands).