Simple definition
realmd simplifies discovery and enrollment of Linux machines into identity domains such as Active Directory.
Purpose and use
realmd simplifies domain discovery and configuration of a Linux client for centralized identity.
How does it work?
It coordinates components such as SSSD and Kerberos; the actual services depend on distribution and domain.
Example and verification
After joining, verify account lookup, authentication and sign-in authorization separately.
Points to watch
Discovering a domain or completing a join does not guarantee that every dependent service and access rule works.
In short
realmd configures integration; underlying components provide the ongoing identity functions.