responding from mobile:
It calls the PowerShell executable with the “command” argument specifying what commands(s) to run within the Powershell session.
The ampersand is the call operator and basically says to run everything within the curly braces. Compress-archive is used for creating a zip archive. Based on the error message you’ve received my guess is that you don’t have Windows PowerShell v5.1 or newer which means you’re probably on something older than Windows 10.