The key difference between the AirPods Pro and the normal AirPods earphones is that the Pros include active noise cancelling and adaptive transparency, whereas the non-Pro AirPods do not. Active noise cancelling means the AirPod Pros can block out external noises far more effectively than the non-Pro models and is a must if you listen in a noisy environment.
Adaptive transparency on the other hand actually amplifies external noise a little, meaning you can clearly hear even with the rubber-tipped AirPods Pro sealing your ear canal.