Difference between Powershell execution states? powershell.exe versus .ps1 file?

I created a task scheduler task, via the MMC GUI to run powershell.exe with some conditions that follow (starting a service).

I notice that this is different than running a .ps1 file or powershell script file. What's the difference between running powershell.exe in the former manner versus running a .ps1 file? It also seemed odd that I was able to get powershell to run by just providing admin credentials, but when running .ps1s, they have to be enabled so as to prevent masquarading .ps1s from causing damage.

Is there a security vulnerability in this?

What is really the difference between running powershell.exe + conditions via say task scheduler and running .ps1 files.

I appreciate your thoughts!