IEEE 802.1X is a network access control standard that provides an authentication mechanism for devices trying to connect to a local area network (LAN). It is commonly used in wired and wireless networks to ensure that only authorized users can access network resources. The standard works by requiring devices to authenticate themselves before they can send or receive data. The process typically involves a supplicant (the device seeking access), an authenticator (the network device, like a switch or access point), and an authentication server (usually a RADIUS server). This three-part system helps maintain network security by verifying user credentials and controlling access based on authentication results.