For example, once you hurt your hands, only the armor in the hand slot is damaged. It is worth noting that armor is just considered for the part which is damaged at the moment.
In order words, the mod will add a “part system” into the game, therefore, your body parts, such as hands, head, feet, and torso will own their own health. Specifically, it aims to change the vanilla health system in order to be divided into different parts. As mentioned above, the main purpose of this mod is to revamp the health system in the Minecraft game world for players.