Netherite armor is the strongest armor in Minecraft, providing the most protection against damage. It is made from netherite ingots, which are found in the Nether dimension. Netherite armor is more durable than diamond armor and provides more protection against fire and lava. It is also the only armor that can be enchanted with the Netherite Upgrade enchantment, which further increases its durability and protection.
To repair netherite armor, you will need to use a smithing table. Place the damaged armor in the leftmost slot of the smithing table, and then place a netherite ingot in the rightmost slot. The smithing table will repair the armor, and the number of repairs that can be made will depend on the durability of the netherite ingot. Netherite ingots can be obtained by smelting ancient debris, which is found in the Nether dimension.