The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.

21.3.2 About Samba Configuration for Windows Workgroups and Domains

Windows systems on an enterprise network usually belong either to a workgroup or to a domain.

Workgroups are usually only configured on networks that connect a small number of computers. A workgroup environment is a peer-to-peer network where systems do not rely on each other for services and there is no centralized management. User accounts, access control, and system resources are configured independently on each system. Such systems can share resources only if configured to do so.

A Samba server can act as a standalone server within a workgroup.

More typically, corporate networks configure domains to allow large numbers of networked systems to be administered centrally. A domain is a group of trusted computers that share security and access control. Systems known as domain controllers provides centralized management and security. Windows domains are usually configured to use Active Directory (AD), which uses the Lightweight Directory Access Protocol (LDAP) to implement versions of Kerberos and DNS providing authentication, access control to domain resources, and name service. Some Windows domains use Windows NT4 security, which does not use Kerberos to perform authentication.

A Samba server can be a member of an AD or NT4 security domain, but it cannot operate as a domain controller. As domain member Samba server must authenticate itself with a domain controller and so is controlled by the security rules of the domain. The domain controller authenticates clients, and the Samba server controls access to printers and network shares.