Are quoata policies a different category than precondition checks?

#1

Dear all,
I’m reading this article https://developer.ibm.com/tutorials/write-istio-mixer-policies/ and there is a separation into three categories for the policies: precondition check, quota, telemetry.
I was wondering how quota policies are different from precondition checks? are thy treated in any different ways?

Thank you in advance for any answers!

#2

@lbudai I did reach to the author of the blog, but he hasn’t responded.