I think a good analogy here is shopping (whether ringing up items at your local convenience store with an old-timey cash register or paper receipt, or a modern digital checkout experience that saves all items digitally in your "cart" before checkout). Each generates a running list of items and subtotal as each item is scanned/added ("saved"). Let's say you change your mind halfway through checkout, and decide not to buy anything after all, because things you thought were on sale weren't after all (now the cashier voids the transaction and rips the half-finished paper receipt out, angrily no doubt--damn, those obnoxious "validation errors"!--and throws it in the trash). Or you get interrupted shopping online and some items stay in your "digital cart" until you come back at some time to actually finish checking out. Only after you finish ringing everything up, pay, and get handed/emailed a receipt, has the transaction actually occurred ("committed"). Prior to that, you couldn't leave the store or bring your stuff back later for a return, because you never actually finished checking out.
Or as another example, let's say only 1 thing rang up the wrong price. So the cashier corrects the price manually after you complain during checkout, based on some instructions from you ("trigger"), but only for your transaction (the next poor sucker will still pay the same mis-advertised price, unless they also ask for it to be fixed/changed in their transaction). There is your "before save" trigger or flow--and execution takes place in the context of the current operation only--updating only that specific record being saved before it is committed.
Only once you've completed your order and paid, is the transaction now complete. Now any subsequent actions that happen later (e.g. return one item for a refund) can occur based on the fact that you committed the final action of actually completing your purchase, checking out, and being handed/emailed your final receipt.
(And the Amazon Return counter at Kohl's is your giant Recycle Bin, where everything you just committed to can get undone! Haha)
Hmmm, is it obvious what I just spent some time doing today? ;)