1.1 Glossary

This document uses the following terms:

Active Directory: The Windows implementation of a general-purpose directory service, which uses LDAP as its primary access protocol. Active Directory stores information about a variety of objects in the network such as user accounts, computer accounts, groups, and all related credential information used by Kerberos [MS-KILE]. Active Directory is either deployed as Active Directory Domain Services (AD DS) or Active Directory Lightweight Directory Services (AD LDS), which are both described in [MS-ADOD]: Active Directory Protocols Overview.

Active Directory Domain Services (AD DS): A directory service (DS) implemented by a domain controller (DC). The DS provides a data store for objects that is distributed across multiple DCs. The DCs interoperate as peers to ensure that a local change to an object replicates correctly across DCs.  AD DS is a deployment of Active Directory [MS-ADTS].

Active Directory Lightweight Directory Services (AD LDS): A directory service (DS) implemented by a domain controller (DC). AD LDS is a deployment of Active Directory [MS-ADTS]. The most significant difference between AD LDS and Active Directory Domain Services (AD DS) is that AD LDS does not host domain naming contexts (domain NCs). A server can host multiple AD LDS DCs. Each DC is an independent AD LDS instance, with its own independent state. AD LDS can be run as an operating system DS or as a directory service provided by a standalone application (Active Directory Application Mode (ADAM)).

attribute: An identifier for a single or multivalued data element that is associated with a directory object. An object consists of its attributes and their values. For example, cn (common name), street (street address), and mail (email addresses) can all be attributes of a user object. An attribute's schema, including the syntax of its values, is defined in an attributeSchema object.

attribute syntax: Specifies the format and range of permissible values of an attribute. The syntax of an attribute is defined by several attributes on the attributeSchema object, as specified in [MS-ADTS] section Attribute syntaxes supported by Active Directory include Boolean, Enumeration, Integer, LargeInteger, String(UTC-Time), Object(DS-DN), and String(Unicode).

Augmented Backus-Naur Form (ABNF): A modified version of Backus-Naur Form (BNF), commonly used by Internet specifications. ABNF notation balances compactness and simplicity with reasonable representational power. ABNF differs from standard BNF in its definitions and uses of naming rules, repetition, alternatives, order-independence, and value ranges. For more information, see [RFC5234].

change log: A log of changes, such as add and delete, that are made to objects that are stored on a back-end database server. Applications can use this information to identify changes that occurred on those objects.

cipher suite: A set of cryptographic algorithms used to encrypt and decrypt files and messages.

digest: The fixed-length output string from a one-way hash function that takes a variable-length input string and is probabilistically unique for every different input string. Also, a cryptographic checksum of a data (octet) stream.

distinguished name (DN): (1) A name that uniquely identifies an object by using the relative distinguished name (RDN) for the object, and the names of container objects and domains that contain the object. The distinguished name (DN) identifies the object and its location in a tree.

(2) In Lightweight Directory Access Protocol (LDAP), an LDAP Distinguished Name, as described in [RFC2251] section 4.1.3. The DN of an object is the DN of its parent, preceded by the RDN of the object. For example: CN=David Thompson, OU=Users, DC=Microsoft, DC=COM. For definitions of CN and OU, see [RFC2256] sections 5.4 and 5.12, respectively.

Generic Security Services (GSS): An Internet standard, as described in [RFC2743], for providing security services to applications. It consists of an application programming interface (GSS-API) set, as well as standards that describe the structure of the security data.

globally unique identifier (GUID): A term used interchangeably with universally unique identifier (UUID) in Microsoft protocol technical documents (TDs). Interchanging the usage of these terms does not imply or require a specific algorithm or mechanism to generate the value. Specifically, the use of this term does not imply or require that the algorithms described in [RFC4122] or [C706] must be used for generating the GUID. See also universally unique identifier (UUID).

Kerberos: An authentication system that enables two parties to exchange private information across an otherwise open network by assigning a unique key (called a ticket) to each user that logs on to the network and then embedding these tickets into messages sent by the users. For more information, see [MS-KILE].

Lightweight Directory Access Protocol (LDAP): The primary access protocol for Active Directory. Lightweight Directory Access Protocol (LDAP) is an industry-standard protocol, established by the Internet Engineering Task Force (IETF), which allows users to query and update information in a directory service (DS), as described in [MS-ADTS]. The Lightweight Directory Access Protocol can be either version 2 [RFC1777] or version 3 [RFC3377].

object class: A set of restrictions on the construction and update of objects. An object class can specify a set of must-have attributes (every object of the class must have at least one value of each) and may-have attributes (every object of the class may have a value of each). An object class can also specify the allowable classes for the parent object of an object in the class. An object class can be defined by single inheritance; an object whose class is defined in this way is a member of all object classes used to derive its most specific class. An object class is defined in a classSchema object. See section 1 of [MS-ADTS] and section 1 of [MS-DRSR].

object identifier (OID): In the context of an object server, a 64-bit number that uniquely identifies an object.

operational attribute: An attribute that is returned only when requested by name in a Lightweight Directory Access Protocol (LDAP) search request. An LDAP search request requesting "all attributes" does not return operational attributes and their values.

protocol data unit (PDU): Information that is delivered as a unit among peer entities of a network and that may contain control information, address information, or data. For more information on remote procedure call (RPC)-specific PDUs, see [C706] section 12.

SASL: The Simple Authentication and Security Layer, as described in [RFC2222]. This is an authentication mechanism used by the Lightweight Directory Access Protocol (LDAP).

schema object: An object that defines an attribute or an object class. Schema objects are contained in the schema naming context (schema NC).

Secure Sockets Layer (SSL): A security protocol that supports confidentiality and integrity of messages in client and server applications that communicate over open networks. SSL supports server and, optionally, client authentication using X.509 certificates [X509] and [RFC5280]. SSL is superseded by Transport Layer Security (TLS). TLS version 1.0 is based on SSL version 3.0 [SSL3].

MAY, SHOULD, MUST, SHOULD NOT, MUST NOT: These terms (in all caps) are used as defined in [RFC2119]. All statements of optional behavior use either MAY, SHOULD, or SHOULD NOT.