I'm having trouble understanding negative reinforcement because from different POVs, it just seems like punishment

My teacher gave the example of the seatbelt alarm in the car that sounds off when you don't put your seatbelt on. It's reinforcement (because we are encouraging the use of a seatbelt) and negative (because we are removing the dinging sound when the seatbelt is used).

Sure that makes sense, but it can also be thought of this way. It's positive (because we are adding a dinging sound that wasn't there before) and a punishment (because we are discouraging driving without a seatbelt).

How can I differentiate the two? It might be helpful to frame it in a child doing something we don't want. Taking away toys in response to bad behavior, in order to decrease bad behavior... vs. only allowing toys to be played with when behaving nicely, in order to increase good behavior. Which is which?