Faceplates and Strike Plates
The faceplate and strike plate protect the parts of the door hardware near the latch as well as the edge of the door and door jamb.
The faceplate is the decorative plate on the edge of the door. It helps guide the tongue and protect the latch. Standard faceplates have either square or radius/rounded edges. When installed correctly, they will sit flush with the edge of the door.
The strike plate attaches to and protects the door jamb. This is the plate the latch-tongue, or deadbolt-tongue will connect with. It should sit flush with the door jamb. Any passage or privacy set needs to have a strike plate for the door to latch. Additionally, deadbolts need a strike plate to properly lock.