Install Windows Server 2012 R2 - MCSA Windows Server 2012 R2: Installation and Configuration Study Guide - page 6

fIguRe 1.1 Available roles in Windows Server 2012 R2

Feature AD CS provides a customizable set of services that allows you to issue and
manage PKI certificates. These certificates can be used in software security systems that
employ public key technologies.
Role AD CS in Windows Server 2012 R2 is the server role that allows you to build a
PKI and provide public key cryptography, digital certificates, and digital signature capa-
bilities for your organization.
Active Directory Domain Services The AD DS server role allows you to create a scalable,
secure, and manageable infrastructure for user and resource management and to provide
support for directory-enabled applications, such as Microsoft Exchange Server.
Active Directory Federation Services Active Directory Federation Services (AD FS)
provides Internet-based clients with a secure identity access solution that works on both
Windows and non-Windows operating systems. AD FS gives users the ability to do a single
sign-on (SSO) and access applications on other networks without needing a secondary
password.
Active Directory Lightweight Directory Services Active Directory Lightweight Directory
Services (AD LDS) is a Lightweight Directory Access Protocol (LDAP) directory service
that provides flexible support for directory-enabled applications, without the dependencies
and domain-related restrictions of AD DS.