Directory Domain Services (ADDS) and became a server role like others. "Active Directory" became the umbrella title of a broader range of directory-based services. According to Byron Hynes, everything related to identity was brought under Active Directory's banner. Active Directory Services Active Directory Services consist of multiple directory services. The best known is Active Directory Domain Services, commonly abbreviated as AD DS or simply AD. Domain Services Active Directory Domain Services (AD DS) is the foundation of every Windows domain network. It stores information about members of the domain, including devices and users, verifies their credentials and defines their access rights. The server running this service is called a domain controller. A domain controller is contacted when a user logs into a device, accesses another device across the network or runs a line-of-business Metro-style app sideloaded into a device. Other Active Directory services (excluding LDS, as described below) as well as most of Microsoft server technologies rely on or use Domain Services; examples include Group Policy, Encrypting File System, BitLocker, Domain Name Services, Remote Desktop Services, Exchange Server and SharePoint Server. The self-managed Active Directory DS must not be confused with managed Azure AD DS, which is a cloud product. Lightweight Directory Services Active Directory Lightweight Directory Services (AD LDS), formerly known as Active Directory Application Mode (ADAM), is an implementation of the LDAP protocol for AD DS. AD LDS runs as a service on Windows Server. AD LDS shares the code base with AD DS and provides the same functionality, including an identical API, but does not require the creation of domains or domain controllers. It provides a Data Store for the storage of directory data and a Directory Service with an LDAP Directory Service Interface. Unlike AD DS, however, multiple AD LDS instances can run on the same server. Certificate Services Active Directory Certificate Services (AD CS) establishes an on-premises public key infrastructure. It can create, validate, revoke and perform other similar actions, public key certificates for internal uses of an organization. These certificates can be used to encrypt files (when used with Encrypting File System), emails (per S/MIME standard), and network traffic (when used by virtual private networks, Transport Layer Security protocol or IPSec protocol). AD CS predates Windows Server 2008, but its name was simply Certificate Services. AD CS requires an AD DS infrastructure. Federation Services Active Directory Federation Services (AD FS) is a single sign-on