Item

Items are objects which only exist within the player's inventory and hands - i.e., they cannot be placed in the game world. Some items simply place blocks or entities into the game world when used. They are thus an item when in the inventory and a block when placed. Some examples of objects which exhibit these properties are item frames, which turn into an entity when placed, and beds, which turn into a group of blocks when placed. When equipped, items and blocks briefly display their names above the HUD.

Items use item IDs while blocks use block IDs.

Materials
Can be obtained by crafting, mining (including breaking blocks), smelting, trading with villagers, killing mobs or finding them in reward chests, which generate in mineshafts, strongholds, blacksmith houses in villages, jungle temples, desert temples, dungeons and nether fortresses. You can also get them by creating a new world with the generate bonus chests option turned on.
 * Mob drops are obtained by picking up the item that drops after a mob dies. Some mobs only drop (certain) items when registered as killed by the player (the spider with spider eyes, and the blaze with blaze rods). Chickens drop (lay) eggs every 5 to 20 minutes. They are used for food, crafting ingredients, brewing ingredients, faster plant-growing, creating other blocks, weapons, and way more.
 * Minerals are obtained by picking up the item that drops after mining an ore with a pickaxe of the right material. They can be used for tools, furnace fuel, creating other blocks, dyes, redstone related blocks, redstone contraptions, and more.
 * Plants (in non-block form, for example: seeds) are obtained by picking up the item that drops after breaking a block-type plant in the world, or are found in reward chests,
 * Dyes. Primary dyes are obtained similar to mob drops, minerals and plants. Examples of these are ink sacs, which are mob drops from squids, lapis lazuli, which is a mineral, and rose reds, which are the output of putting red plants in a crafting grid. Secondary and tertiary dyes are obtained by combining two primary or secondary dyes together in a crafting grid, examples are lime, cyan, purple, gray and more dyes. They are used to color certain blocks or sheep to get their respective color of wool when shearing them.
 * (Leftover) Crafting Ingredients are obtained by a lot of causes. Most crafting ingredients have another category to them as well. Leftover crafting ingredients are ingredients that have no category, and no other non-decoration purpose than creating other blocks or items, examples are flint, bowls, sticks, sugar, paper, books, clay items, brick items, netherbrick items, and netherquartz items.
 * Brewing Ingredients are obtained by a lot of causes. These are ingredients necessary to create potions, examples are blaze powder, ghast tears, glistering melons, and more. For better potions effects you can add glowstone to make a potion tier two, or redstone to extend the duration of the potion. Glowstone and redstone cannot be combined together on one potion.
 * Enchanting Ingredients are obtained by trading, or by creating a new item. These are ingredients only used for enchanting, examples are enchanted books and experience bottles

Food
Is found or crafted by the player and eaten to regain hunger points and saturation. Some food will give status (potion) effects to the player.
 * Normal Food such as apples, bread, melons, pumpkin pie, steak and more, will only give back hunger points and saturation without giving any other effect.
 * Good Food such as golden apples can give the player (several) good status effects, such as regeneration, absorption, fire resistance and resistance.
 * Bad Food such as raw chicken, rotten flesh, spider eyes and pufferfish can give the player (several) bad status effects, such as hunger, poison and nausea. If you are about to starve and only have this food, after eating it you can drink milk to clear all status effects.

Tools
Are used for a variety of purposes.
 * Axes and Shovels allow the player to break certain blocks faster than mining by hand. They can be made from wood, stone, iron, gold and diamond.
 * Pickaxes allow the player to break certain blocks faster than mining by hand too, but are required in different types of materials in order to retrieve resources from stone-type blocks. They can be made from wood, stone, iron, gold and diamond.
 * Hoes allow the player to till dirt, allowing them to plant crops like seeds, carrots, potatoes, melon seeds and pumpkin seeds. They can be crafted in wood, stone, iron, gold and diamond.
 * Buckets allow the player to transport liquids such as water and lava, and getting milk by right-clicking a cow.
 * Shears allow the player to collect wool from sheep, red mushrooms from mooshrooms, string from cobwebs, with a silk touch enchantment the cobweb itself, and break varieties of tall grass, leaves, vines and dead bushes for the actual blocks too. They can also be used to break and collect tripwire without creating a redstone charge.
 * Flint And Steel allows the player to set blocks on fire for varying periods of time, some blocks will be burned (destroyed without an item drop) by this process. They also allow the player to light a nether portal on fire, so that nether portal blocks are formed inside. A fire charge also has the same effect, but it does not have durability and will be used up after one use. They can also be used as a ranged projectile fired from dispensers as opposed to a tool.
 * Fishing Rods allow the player to go fishing to catch several types of fish, treasure, and trash, as well as pulling mobs closer.
 * Informative Tools assist the player in navigating the world and telling time respectively.
 * Maps are items where when looked at blocks rendered in the map are shown as pixels.
 * Compasses will always point exactly with their red arrow at the player's original spawn point.
 * Clocks will show the player what time it is in their world.

Weapons
Are mostly used to kill mobs and other players faster.
 * Swords are used to kill mobs and other players faster, to block attacks which reduces most types of damage by half, or to break blocks a little faster.
 * Bows (With Arrows) are used to kill mobs or other players faster from range.
 * Snowballs can be used to knock players or mobs back, giving you time to run. They only cause damage to Ender Dragons or Blazes. This is also a crafting ingredient.
 * Eggs can be used to knock players or mobs back, giving you time to run. They do not deal damage.
 * Fishing Rods can be used to knock players or mobs back, giving you time to run. They do not deal damage, and can also be used to pull mobs and players towards you, giving people using ranged combat no advantage.
 * Enderpearls to teleport away or into combat. You will take 2.5 hearts of damage but the Feather Falling enchantment will reduce this. This is also a mob drop and crafting ingredient.
 * Flint and Steel, Fire Charges and Lava Buckets can be used to set players on fire.
 * Empty Buckets can be used to steal someone else's lava or water, giving them a disadvantage.

Armor
Reduces damage from mobs, players, lava, and explosions. Armor enchants increase this.
 * Helmets, Chestplates, Leggings and Boots are a full set of player armor that reduces damage for a player or mob. Zombies and skeletons can rarely drop this if they spawned wearing it. When a player throws armor (or any item) at a zombie or skeleton, and it gets picked up by them, they will drop it upon (any kind of) death.
 * Horse Armor is used to protect a horse from damage similar to player armor, but can only be worn by a tamed horse.
 * Water Buckets can be used to put the player or players on fire out.
 * Milk can be used to erase all status effects.

Transportation
Items/entities allow the player to move themselves, mobs or items over land or water with relative speed and ease.
 * Minecarts are used to travel much faster across rails, they are also used to store and pick up items or work in and activate redstone circuitry.
 * Boats are used to travel much faster across water (for example over oceans, rivers and lakes).
 * Saddles and Carrots on sticks are needed to travel on pigs and/or horses.
 * Leads can be used by right-clicking most passive mobs, and will make them follow you and they'll get pulled closer when they're too far away from you. If they can't get to you and the distance is too far the lead will break on the place of where the mob is.
 * If Wheat, Carrots and varieties of Seeds are held, most passive mobs will follow you.

Potions
Are craftable, drinkable and throwable items that confer specific effects. Producing them mostly requires resources from the nether. In order to create a splash potion (throwable potion), you need to add gunpowder to any normal potion. This change cannot be reversed.

Music Discs
Are musical items textured like discs, that when put in a jukebox will create music. They are obtained by letting a creeper die by a skeleton's arrow shot, or (two different ones) are found in dungeon chests. There are twelve different discs in the game.

Eggs and Spawn Eggs

 * If eggs are used they will have a chance of spawning one to four baby chickens.
 * Spawn Eggs are re-textured eggs used to spawn in most mobs in the game, and are obtainable only in creative mode. Right-clicking the same type of spawn egg on a mob that can have babies will spawn a baby mob on that place (all wolves and all passive mobs can have babies except squids and bats).

Decorations
Are items that only have aesthetic purposes.
 * Fireworks can be crafted in varieties of colors, shapes and sounds and when used will quickly fly up in the air creating a beautiful scenery.
 * Book And Quills can be used to write down information in a book.

Other
Other items are used for miscellaneous purposes. Logic Components In Redstone Circuits, and Nametags to name any kind of mob, and keep them from despawning. Naming a mob "Dinnerbone" or "Grumm" will turn them upside down.