It is a process for authenticating, authorizing and accounting user dynamically, who is joining the network with wired connection its is done with the AAA server setup using 802.1X protocol for end devices which are capable of providing authentication information (username & password).

hope you have got your query resolved for getting more details on this it is recommended to do a course on CCIE security https://www.networkbulls.com/training-ccie-security-india 

thanks & cheers