Answer:
Protraction and retraction are opposite of each other.
Explanation: For example, here are difference between the two.
1. Protraction occurs when the lower has is pushed forward to stick to the chin, Retraction, being the opposite pulls the lower jaw backward.
2. Scapular retraction, this help to move the shoulder blade(scapula) towards the spine, also Protraction being the opposite help to move the shoulder blade away from the spine.