On Item Add/Update: If a user edit an item and item goes to pending status as the item needs approval, the approving teams need to be notified that an item is waiting for their approval.
On Item Approved: If the approving team approve the item,the user who added/updated the item needs to be notified.
I should also point out that I know the difference between a metaphor and simile in case that was bothering you from the opening sentence.
I am nothing if not a masterful linguist after a beer or two or more.
On Item rejected: If the approving team reject the item, the user who added/updated the item needs to be notified with reasons why the item rejected.