You can configure ESXi to use a directory service such as Active Directory to manage users.
Creating local user accounts on each host presents challenges with having to synchronize account names and passwords across multiple hosts. Join ESXi hosts to an Active Directory domain to eliminate the need to create and maintain local user accounts. Using Active Directory for user authentication simplifies the ESXi host configuration and reduces the risk for configuration issues that could lead to unauthorized access.
When you use Active Directory, users supply their Active Directory credentials and the domain name of the Active Directory server when adding a host to a domain.