Measure-Object

Calculates the numeric properties of objects, and the characters, words, and lines in string objects, such as files of text. Note: This command can only be used through PowerShell. More information: https://learn.microsoft.com/powershell/module/microsoft.powershell.utility/measure-object.

Count the files and folders in a directory:

Get-ChildItem | Measure-Object

Pipe input to Measure-Command (objects that are piped to Measure-Command are available to the script block that is passed to the Expression parameter):

"One", "Two", "Three", "Four" | Set-Content -Path "{{path\to\file}}"; Get-Content "{{path\to\file}}"; | Measure-Object -Character -Line -Word