There are four different materials that you can craft armor out of. Leather, Gold, Iron, and Diamond. In older versions of Minecraft that lack the Leather item, you can use Wool to create armor instead.
Leather armor is the most frail and weak armor, not even giving you four full shirts of protection and having the lowest durability. Generally speaking you can get iron quite easily, so leather armor is usually not to be used. The most important feature of leather armor is that it is infinitely replaceable- as long as you keep a herd of cows, you can keep growing wheat, breeding cows, and killing them for leather (and meat, which is also very important while you’re exploring dangerous areas).
Gold armor is the second hardest to make, with gold being a rather rare resource, and is -usually- a waste if you have anything at all else to do with your gold that’s worthwhile. Roughly half-again as durable as leather armor, a full suit of golden armor will give you only 44% reduction in damage. While this is considerably better than the 28% that leather gives you, it’s really nothing all that good. There is one advantage to golden armor, though it’s unlikely to matter until the much later stages of the game- gold armor is far and away the best armor to enchant, being nearly twice as enchantable as leather and two-and-a-half times as enchantable as diamond armor. Keep that in mind for later, but usually it’s not going to be worth the concern.
Iron armor, the most commonly used thanks to the paucity of diamond in most worlds, grants a whopping 60% damage reduction, and is easily twice as durable as gold armor. While it is also the least enchantable armor, that is hardly a major failing because by the time you’re really worried about enchanting, you probably have a suit of diamond armor for heavy combat and the iron stuff is just for general exploring and digging.
Finally, there is diamond armor. Very expensive, it is the unquestionable top-of-the-line armor suit, granting the full 80% damage reduction, and being notably more than twice as durable as iron armor. Unfortunately, it is rather hard to enchant, with iron armor being the only type more difficult. Still, you’re likely to find yourself using this for major battles (such as the large final fight, or busting your way into a spawner room). Just take care with it- it won’t break for a long time, but if you let it break instead of repairing it, you’re out a lot of resources- a total of 24 diamonds.
