What type of solution is at the core of virtually all directory services?

The Lightweight Directory Access Protocol (LDAP) forms the basis of virtually all directory services, regardless of the specific vendor or software package.WS is a protocol for information exchange between two systems and does not actually store the data. ADFS is a Windows component for enabling single sign-on for the operating system and applications, but it relies on data from an LDAP server. PKI is used for managing and issuing security certificates.