Difference between folder-action and snapshot-root-action

May be because I’m not English fluent speaker, but can’t see the difference between folder-action and snapshot-root-action. Both configured commands seem to run (before or after) every snapshot.
What’s the difference?

from document actions

--before-folder-action and --after-folder-action are not inherited and must be set explicitly on target folders, while --before-snapshot-root-action and --after-snapshot-root-action are inherited from their parents and can be set at global, host, user or directory level

Hi, sorry I still don’t understand this. could you provide an example showing how they differ if you don’t mind?

I have a ntfy account that I use to trigger a notification to myself when something I’m running fails, I am hoping I can use this with kopia ui using “after folder” or “after snapshot” commands (just using curl command) but I am confused about the difference between the two and also how to trigger only on error. That’s what led me here to you.