WhatIsAPowerShellModule

What is a PowerShell Module

Before going further, it’s important to understand what PowerShell is.

PowerShell is a scripting and automation platform built on top of the .NET framework. It allows users to interact with the operating system and installed products by running cmdlets (pronounced command‑lets). With just a few lines of code, cmdlets can perform tasks that would otherwise require many manual steps.

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What Are Cmdlets?

Cmdlets are pre‑built PowerShell functions designed to perform a specific task.

Like functions in most programming languages, cmdlets:

• Can accept input
• Can return output (usually objects)
• Perform a focused action

For example, to retrieve a list of Windows services on your local machine, you can run:

Get-Service

This will return all Services with their associated properties, like status, name, displayName etc.

PowerShell Modules

Cmdlets are delivered and organized through PowerShell modules.

A PowerShell module is a collection of related functionality packaged together. At its core, a module includes a .psm1 file, which defines the cmdlets and functions the module exposes. Modules often include additional supporting files, such as:

• .dll files containing compiled code that perform the underlying work
• Help and documentation files
• Resource files and localization data

This modular approach allows PowerShell to remain lightweight while still supporting a wide range of technologies.

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Extending PowerShell

PowerShell ships with many built‑in cmdlets for managing Windows, but it does not include cmdlets for every product or platform by default.

To work with additional technologies, PowerShell can be extended by installing extra modules. For example, to manage Active Directory, you must install the Active Directory module (typically provided through RSAT).

Once the module is installed, it exposes cmdlets specifically designed for working with Active Directory objects, such as:

Get-ADUser

This cmdlet allows you to retrieve and manage user accounts in Active Directory—capabilities that are unavailable until the module is installed.