Windows Server Definitions

This glossary explains the meaning of key words and phrases that information technology (IT) and business professionals use when discussing Microsoft Windows Server and related software products. You can find additional definitions by visiting WhatIs.com or using the search box below.

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  • A

    Active Directory forest (AD forest)

    An Active Directory forest is the highest level of organization within Active Directory.

  • Active Directory functional levels

    Active Directory functional levels are controls that specify which advanced Active Directory domain features can be used in an enterprise domain.

  • Active Directory tree

    An Active Directory (AD) tree is a collection of domains within a Microsoft Active Directory network.

  • Azure DevOps

    Azure DevOps -- rebranded from Visual Studio Team Services (VSTS) in 2018 -- is a software-as-a service (SaaS) platform from Microsoft designed to provide a comprehensive toolchain for developing and deploying software projects.

  • What is Active Directory (AD)?

    Active Directory (AD) is Microsoft's proprietary directory service that enables network admins to manage users, permissions and their access to networking resources.

  • What is Active Directory Domain (AD Domain)?

    An Active Directory domain (AD domain) is a collection of objects within a Microsoft Active Directory network. An object can be a single user or a group, or it can be a hardware component, such as a computer or printer. Each domain holds a database containing object identity information.

  • B

    boot

    To boot (to boot up, to start up or booting) a computer is to load an operating system (OS) into the computer's main memory or random-access memory (RAM).

  • built-in administrator account

    In the Windows operating system, the built-in administrator account -- the first account created when the OS was installed -- has the highest permissions of any profile on the computer system.

  • What is a batch file?

    A batch file is a script file that stores commands to be executed in a serial order.

  • What is the blue screen of death (BSOD)?

    The blue screen of death (BSOD) -- also known as a stop error screen, blue screen error, fatal error or bugcheck -- is a critical error screen that can be displayed by Microsoft Windows operating systems (OSes).

  • C

    canonical name (CNAME)

    A canonical name (CNAME) is a type of Domain Name System (DNS) database record that indicates that a domain name is the nickname or alias for another domain name.

  • Client Access Server (CAS)

    The Client Access Server (CAS) is a server role that handles all client connections to Exchange Server 2010 and Exchange 2013.

  • client-server network

    A client-server network is a distributed communications architecture in which a centralized server receives and responds to requests for services and data from multiple clients.

  • command-line interface (CLI)

    A command-line interface (CLI) is a text-based user interface (UI) used to run programs, manage computer files and interact with the computer.

  • computer

    A computer is a device that accepts information (in the form of digitalized data) and manipulates it for some result based on a program, software, or sequence of instructions on how the data is to be processed.

  • Ctrl-Alt-Delete

    On a personal computer with the Microsoft Windows operating system, Control+Alt+Delete is the combination of the Ctrl key, the Alt key, and Del key that a user can press at the same time to terminate an application task or to reboot the operating system.

  • What is C (programming language)?

    The C programming language is a procedural and general-purpose language that provides low-level access to system memory.

  • D

    defragmentation

    Defragmentation is the process of locating the noncontiguous fragments of data into which a computer file may be divided as it is stored on a hard disk, and rearranging the fragments and restoring them into fewer fragments or into the whole file.

  • Directory Services Restore Mode (DSRM)

    Directory Services Restore Mode (DSRM) is a Safe Mode boot option for Windows Server domain controllers.

  • diskpart (Disk Partition Utility)

    Diskpart is a command line utility in Windows operating systems (OSs) that is used to manage disks, partitions, and volumes.

  • dynamic link library (DLL)

    A dynamic link library (DLL) is a collection of small programs that larger programs can load when needed to complete specific tasks.

  • What is a domain controller?

    A domain controller is a server that processes requests for authentication from users and computers within a computer domain.

  • E

    Exchange Management Console (EMC)

    The Exchange Management Console (EMC), introduced by Microsoft in 2007, is an administrative tool with a graphical user interface (GUI) that's used to manage the components and resources of Microsoft Exchange Server.

  • Exchange Online

    Exchange Online is the hosted version of Microsoft's Exchange Server messaging platform that organizations can obtain as a stand-alone service or via an Office 365 subscription.

  • Exchange Web Services (EWS)

    Microsoft Exchange Web Services (EWS) is an application program interface (API) that lets applications access items in a Microsoft Exchange email mailbox, such as calendars, contacts, and messages.

  • F

    failover cluster

    In computing, a failover cluster refers to a group of independent servers that work together to maintain high availability of applications and services.

  • G

    global catalog (Active Directory)

    A global catalog is a data storage source containing partial representations of objects found in a multi-domain Active Directory Domain Services forest.

  • Group Policy

    Group Policy is a management feature in Microsoft's Active Directory (AD) that enables network and system administrators to configure and assign user and computer settings in an AD environment.

  • Group Policy Management Console (GPMC)

    Group Policy Management Console (GPMC) is a Microsoft Management Console snap-in that provides a graphical user interface that enables Active Directory (AD) administrators to manage Group Policy Objects (GPOs) from one console.

  • GUID (global unique identifier)

    A GUID (globally unique identifier) is a 128-bit text string that represents an identification (ID).

  • What is Group Policy Object (GPO) and why is it important?

    Microsoft’s Group Policy Object (GPO) is a collection of Group Policy settings that defines what a system will look like and how it will behave for a defined group of users.

  • H

    hotfix

    A hotfix is code -- sometimes called a patch -- that fixes a bug in a product.

  • I

    Internet Information Services (IIS)

    Internet Information Services (IIS) is a flexible, general-purpose web server from Microsoft that runs on Windows systems to serve requested HTML pages or files.

  • What is ISA (Industry Standard Architecture)?

    ISA (Industry Standard Architecture) is a standard bus (computer interconnection) architecture that was associated with the IBM AT motherboard.

  • L

    Linux Secure Boot

    Linux Secure Boot is a Hyper-V feature that Microsoft introduced in Windows 10 and Windows Server 2016. The feature allows specific Linux distributions to boot properly when running in Hyper-V generation 2 virtual machines.

  • Local Group Policy Editor

    Local Group Policy Editor is a Microsoft Management Console (MMC) snap-in that provides a user interface for managing local Group Policy settings on a Windows computer.

  • M

    Active Directory Domain Services (AD DS)

    Active Directory Domain Services (AD DS) is a server role in Active Directory that allows admins to manage and store information about resources from a network, as well as application data, in a distributed database.

  • Microsoft Active Directory Migration Tool (ADMT)

    The Microsoft Active Directory Migration Tool (ADMT) is a free utility administrators can use to move Active Directory objects, such as computers, users and groups, from one Windows Server Active Directory domain or forest to another.

  • Microsoft Azure ExpressRoute

    Microsoft Azure ExpressRoute is a service that provides a private connection between an organization's on-premises infrastructure and Microsoft Azure data centers.

  • Microsoft Azure Key Vault

    Microsoft Azure Key Vault is a cloud-based security service offered by Microsoft as part of its Azure platform.

  • Microsoft Azure Stack

    Microsoft Azure Stack is an integrated platform of hardware and software that delivers Microsoft Azure public cloud services in a local data center to enable organizations to construct hybrid clouds.

  • Microsoft Certified Systems Engineer (MCSE)

    The Microsoft Certified Systems Engineer (MCSE) is a certification that was offered by Microsoft for IT professionals who demonstrated expertise in designing, implementing, and administering Windows server infrastructure, as well as other Microsoft technologies.

  • Microsoft Cloud Witness

    Microsoft Cloud Witness is a quorum witness for Windows Server Failover Clustering (WSFC) that uses Microsoft Azure as the arbitration point.

  • Microsoft Exchange Mailbox Replication Service (MRS)

    The Microsoft Exchange Mailbox Replication Service (MRS) is a feature that handles mailbox import, export, migration and restoration requests on Exchange Server.

  • Microsoft Exchange Online Protection (EOP)

    Microsoft Exchange Online Protection (EOP) is a cloud-based service that provides email filtering designed to protect organizations against spam, malware, and other email-based threats.

  • Microsoft Exchange Server

    Microsoft Exchange Server is Microsoft's email, calendaring, contact, scheduling and collaboration platform.

  • Microsoft Hybrid Configuration Wizard

    The Microsoft Hybrid Configuration Wizard (HCW) is a tool provided by Microsoft to help organizations set up and configure a hybrid deployment between their on-premises Exchange Server and Exchange Online, which is part of Microsoft 365.

  • Microsoft Hyper-V Shielded VM

    A Microsoft Hyper-V Shielded VM is a security feature of Windows Server 2016 that protects a Hyper-V second-generation virtual machine (VM) from access or tampering by using a combination of Secure Boot, BitLocker encryption, virtual Trusted Platform Module (TPM) and the Host Guardian Service.

  • Microsoft Identity Manager

    Microsoft Identity Manager -- also called Microsoft Identity Manager 2016 or MIM -- is an on-premises tool that enables organizations to manage access, users, policies and credentials.

  • Microsoft Monitoring Agent (MMA)

    Microsoft Monitoring Agent (MMA) is a service used to watch and report on application and system health on a Windows computer.

  • Microsoft Nano Server

    Microsoft Nano Server is a lightweight version of the Windows Server operating system that was introduced with Windows Server 2016 for use as an OS layer for virtualized container instances.

  • Microsoft Network Device Enrollment Service (NDES)

    Microsoft Network Device Enrollment Service (NDES) is a security feature in Windows Server 2008 R2 and later Windows Server operating versions. NDES provides and manages certificates used to authenticate traffic and implement secure network communication with devices that might not otherwise possess valid domain credentials.

  • Microsoft Network Policy and Access Services (Microsoft NPAS)

    Microsoft Network Policy and Access Services (Microsoft NPAS) is a server role in Windows 2008 and Windows Server 2012 that allows administrators to provide local and remote network access.

  • Microsoft Office 365 Admin Center

    The Microsoft Office 365 Admin Center is the web-based portal administrators use to manage user accounts and configuration settings for the Office 365 subscription services, including Exchange Online and SharePoint Online.

  • Microsoft Office 365 Advanced Threat Protection

    Microsoft Office 365 Advanced Threat Protection (ATP) is Microsoft's optional cloud-based service that scans and filters email to protect subscribers from malware in attachments and hyperlinks to malicious websites.

  • Microsoft Online Services Sign-In Assistant

    The Microsoft Online Services Sign-In Assistant is a software application that provides common sign-on capabilities for a suite of Microsoft online services, such as Office 365.

  • Microsoft Outlook on the web (formerly Outlook Web App, OWA)

    Outlook on the web is the browser-based email client for users to access email, calendars, tasks and contacts from Microsoft's on-premises Exchange Server and cloud-based Exchange Online.

  • Microsoft Remote Desktop Web Access (Microsoft RD Web Access)

    Microsoft Remote Desktop Web Access (Microsoft RD Web Access) is a Remote Desktop Services role in some versions of the Windows Server OS.

  • Microsoft SCOM (System Center Operations Manager)

    Microsoft SCOM (System Center Operations Manager) is a set of tools for infrastructure monitoring and application performance management.

  • Microsoft Software Assurance (SA)

    Microsoft Software Assurance is a software maintenance program that helps organizations gain access to the latest software versions and releases, without incurring additional licensing costs.

  • Microsoft System Center

    Microsoft System Center is a suite of software products designed to simplify the deployment, configuration and management of IT infrastructure and virtualized software-defined data centers.

  • Microsoft System Center 2012

    Microsoft System Center 2012 is a bundled suite of systems management products that offers tools to monitor and automate virtualized environments, including private clouds based on Microsoft Hyper-V.

  • Microsoft System Center Configuration Manager (SCCM)

    Microsoft System Center Configuration Manager (SCCM) is a Windows product that enables the management, deployment and security of devices and applications across an enterprise.

  • Microsoft System Center Operations Manager Management Pack (Microsoft SCOM Management Pack)

    A System Center Operations Manager (SCOM) Management Pack is a pre-fabricated rule set intended to extend and configure SCOM for specific services or applications.

  • Microsoft Technology Associate (MTA) certification

    Microsoft Technology Associate (MTA) certification is the name of a suite of entry-level certifications offered by Microsoft that signify fundamental technology knowledge in those who earn it.

  • Microsoft Windows Azure Active Directory (Windows Azure AD)

    Microsoft Windows Azure Active Directory (Windows Azure AD or Azure AD) is a cloud service that provides administrators with the ability to manage end-user identities and access privileges.

  • Microsoft Windows Background Intelligent Transfer Service (BITS)

    Microsoft Windows Background Intelligent Transfer Service (BITS) is a service in Microsoft Windows operating systems (OSes) that allows download from and upload of files to Hypertext Transfer Protocol (HTTP) web servers and Server Message Block (SMB) file servers.

  • Microsoft Windows Features on Demand

    Microsoft Windows Features on Demand is a feature that allows system administrators to add or remove roles and features in Windows 8 and Windows Server 2012, and later versions of the client and server operating system to alter the file size of those operating systems.

  • Microsoft Windows PowerShell DSC (Desired State Configuration)

    Desired State Configuration (DSC) is a feature in PowerShell 4.0 and above that helps administrators to automate the configuration of Windows and Linux operating systems.

  • Microsoft Windows PowerShell Integrated Scripting Environment (ISE)

    The Windows PowerShell Integrated Scripting Environment (ISE) is a graphical user interface and front-end hosting application for Windows PowerShell.

  • Microsoft Windows Server 2016

    Microsoft Windows Server 2016 is Microsoft's server operating system (OS).

  • Microsoft Windows Server LTSC (Long-Term Servicing Channel)

    Microsoft Windows Server LTSC (Long-Term Servicing Channel) is one of the servicing options available for users of the Windows Server operating system (OS).

  • Microsoft Windows Server OS (operating system)

    Microsoft Windows Server OS (operating system) is a series of enterprise-class server operating systems designed to share services with multiple users and provide extensive administrative control of data storage, applications and corporate networks.

  • Microsoft Windows Subsystem for Linux (WSL)

    Microsoft Windows Subsystem for Linux (WSL) is a series of Microsoft components that allow native Linux 64-bit Executable and Linkable Format (ELF64) binaries to run on the Windows kernel in the Windows 10 operating system (OS).

  • Microsoft Windows Update

    Microsoft Windows Update is a security service for Windows users that, once activated, automatically searches for and installs updates.

  • Monad Manifesto

    The Monad Manifesto is a document written by Jeffrey Snover in 2002 that outlined his idea for a new Windows systems administration tool named Monad, which was changed to Windows PowerShell.

  • What is Microsoft Azure File Service?

    Microsoft Azure Files -- sometimes known as Microsoft Azure File Service -- is a simple, secure, serverless, fully managed and cloud-based file sharing service for enterprise users.

  • What is Microsoft Outlook?

    Microsoft Outlook is an email, contacts and calendar program from Microsoft.

  • What is Microsoft?

    Microsoft is the world's largest vendor of computer software and a leading provider of cloud computing services, video games, computer and gaming hardware, search and other online services.

  • Windows Admin Center

    Windows Admin Center (WAC), formerly Microsoft Project Honolulu, is a browser-based management tool from Microsoft that allows administrators to manage Windows servers and clusters from a centralized, graphical user interface.

  • Windows containers

    Windows containers provide abstracted, isolated, lightweight and portable operating environments for application development on a single system.

  • N

    NDIS (Network Driver Interface Specification)

    Network Driver Interface Specification (NDIS) is a Microsoft Windows specification for how communication protocol programs (such as TCP/IP) and network device drivers should communicate with each other.

  • NTFS (NT File System)

    NTFS, which stands for 'NT file system' and the 'New Technology File System,' is the file system that the Windows NT operating system (OS) uses for storing and retrieving files on hard disk drives (HDDs) and solid-state drives (SSDs).

  • O

    Open Document Format (ODF)

    The Open Document Format (ODF) is a zip-compressed, Extensible Markup Language (XML)-based, open source file format for saving and exchanging text, spreadsheets, charts, graphics and presentations.

  • organizational unit (OU)

    An organizational unit (OU) can refer to different things depending on the context, such as an organizational group within a company that is intended to accomplish a specific business function.

  • Outlook Anywhere

    Microsoft Outlook Anywhere is a software feature that lets clients using Outlook 2010, Outlook 2007, or Outlook 2003 connect to the Microsoft Exchange server and access their email from outside the corporate domain without having to use a virtual private network (VPN).

  • P

    peer-to-peer network (P2P network)

    A peer-to-peer (P2P) network is a network in which each computer functions as a client or server for other computers in the network.

  • Preboot Execution Environment (PXE)

    The Preboot Execution Environment or PXE (commonly pronounced as pixie) is a client-server environment that enables network computers to boot over the network interface card (NIC), instead of from a CD-ROM or hard disk.

  • What is PowerShell and how to use it: The ultimate tutorial

    PowerShell is an object-oriented automation engine and scripting language with an interactive command-line shell that Microsoft developed to help IT professionals configure systems and automate administrative tasks.

  • R

    read-only

    Read-only is a file attribute which only allows a user to view a file, restricting any writing to the file.

  • remote code execution (RCE)

    Remote code execution (RCE) is when an attacker accesses a target computing device and makes changes remotely, no matter where the device is geographically located.

  • Resilient File System (ReFS)

    A Resilient File System (ReFS) is a file system that Microsoft developed for use on a Windows operating system (OS) and is designed to overcome some of the limitations in the New Technology File System (NTFS).

  • restore point

    A system restore point is a backup copy of important Windows operating system (OS) files and settings that can be used to recover the system to an earlier point of time in the event of system failure or instability.

  • Resultant Set of Policy (RSoP)

    Resultant Set of Policy (RSoP) refers to all the group policies applied to a user and computer.

  • RSAT (Remote Server Administration Tools)

    RSAT (Remote Server Administration Tools) refers to a set of tools from Microsoft that enable IT administrators to remotely manage roles and features in Windows Server from a computer that is running Windows 11, Windows 10 or Windows 7 Service Pack 1.

  • S

    computer system

    A computer system consists of hardware components that have been carefully chosen so that they work well together and software components or programs that run in the computer.

  • service desk

    An IT service desk is a communications center that provides a single point of contact (SPOC) between a company, its customers, employees and business partners.

  • SharePoint Online

    Microsoft SharePoint Online is a collection of cloud- and web-based technologies that make it easy for organizations to store, share and manage digital information.

  • SMB 3.0 (Server Message Block 3.0)

    SMB 3 (Server Message Block 3.0) is a protocol that provides a way for a computer's client applications to read and write to files from a server in a computer network.

  • swap file (swap space or page file)

    A swap file is a system file that creates temporary storage space on a solid-state drive or hard disk when the system runs low on memory.