What is PowerShell?¶

PowerShell is a cross-platform task automation shell and scripting language built on .NET. It was first released by Microsoft in 2006 as Windows PowerShell and open-sourced in 2016 as PowerShell Core (now simply PowerShell 7+).

The Key Difference: Objects, Not Text¶

Traditional shells like Bash communicate between commands using plain text. To extract information you must parse strings, which is fragile and error-prone:

Bash — text parsing is brittle

ps aux | grep "[n]otepad" | awk '{print $2}'   # parse PID from text

PowerShell passes .NET objects between commands. Every property is accessible by name — no parsing required:

PowerShell — structured objects

(Get-Process -Name notepad).Id   # access the Id property directly

This object model makes PowerShell uniquely powerful for scripting, data manipulation, and automation.

PowerShell vs. Windows PowerShell¶

	Windows PowerShell	PowerShell 7+
Runtime	.NET Framework	.NET 8 / 9
Platforms	Windows only	Windows, macOS, Linux
Version	5.1 (final)	7.x (actively updated)
Executable	`powershell.exe`	`pwsh.exe`
Status	Maintenance only	Active development

Which should I use?

Use PowerShell 7+ (pwsh) for all new scripts. Windows PowerShell 5.1 (powershell) is still available on Windows but receives no new features.

Core Design Principles¶

1. Verb-Noun Naming¶

Every cmdlet follows a Verb-Noun naming convention:

Verb	Noun	Cmdlet
`Get`	`Process`	`Get-Process`
`Stop`	`Service`	`Stop-Service`
`Export`	`Csv`	`Export-Csv`
`Invoke`	`RestMethod`	`Invoke-RestMethod`

The approved verb list (Get-Verb) keeps commands predictable — once you know the nouns in a module, you can guess the cmdlets.

2. Everything is an Object¶

$file = Get-Item .\README.md
$file.Length          # file size in bytes
$file.LastWriteTime   # DateTime object
$file.Extension       # ".md"

3. The Pipeline¶

Commands are chained with |. The output object of one command becomes the input of the next:

Get-Service |
    Where-Object Status -eq 'Stopped' |
    Sort-Object DisplayName |
    Select-Object Name, DisplayName |
    Export-Csv .\stopped-services.csv -NoTypeInformation

4. Discoverability¶

Three commands let you explore anything:

Get-Command *dns*          # find cmdlets by name
Get-Help Resolve-DnsName   # read documentation
Get-Process | Get-Member   # inspect object properties

Where PowerShell Runs¶

Windows — built-in (5.1) and downloadable (7+)
macOS — via Homebrew or direct download
Linux — via package managers (apt, dnf, snap) or direct download
Azure Cloud Shell — pre-installed
VS Code — with the PowerShell extension
Windows Terminal — fully supported

Next Step¶

Install PowerShell