Item

Items are objects which only exist within the player's inventory and hands - which means, 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 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. They are used for food, crafting ingredients, brewing ingredients, faster plant-growing, creating other blocks, weapons, and more. Some mobs won't drop (certain) items when not 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.
 * Minerals are obtained by picking up the item that drops after smelting an ore, or 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. They are used for creating crops when placed on farmland.
 * Dyes are used to color certain blocks, or sheep to get their respective color of wool when shearing them. 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.
 * (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 specific category and no other non-decoration purpose than to create 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 dust to make a tier two potion, or redstone to extend the duration. These two cannot be legitimately combined together on one potion.
 * Enchanting Ingredients are obtained by trading with a villager, or by crafting 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 items 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 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, you can drink milk after eating it to clear all their bad 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 crafted from wood, stone, iron, gold and diamond.
 * Pickaxes allow the player to break certain blocks faster than mining by hand, but are required in different types of materials in order to retrieve resources from specific stone-type blocks. They can be crafted 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 from 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. They can also be used to break and collect tripwire without activating adjacent redstone dust.
 * Flint And Steel allows the player to set most 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 nether portals on fire, so that nether portal blocks are formed inside. A fire charge has the same (and more) effects, but will be used up after one use.
 * 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 colored pixels, respective to the rendered block.
 * Compasses will always point exactly with their red arrow at the player's "original" spawn point. (For players with Pre-release Alpha and Beta worlds, may have had this point "shift" as spawn points were/are coded in the region files, not derived from the seed. For more on this, see spawn point.)
 * Clocks will show the player what time it is in their world. Clocks will rapidly spin when they're located in the nether or the end.

Weapons
Are mostly used to kill mobs and players (faster).
 * Swords are used to kill mobs and 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 players from a distance.
 * Snowballs can be used to knock players or mobs back, giving you time to run. They only deal 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 can be used to teleport away or into combat. When used, the player will take 2.5 hearts of damage but feather falling and protection enchantments 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 a player'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 they pick it up, 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 a player on fire out.
 * Milk can be used to erase all status (potion) 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. Mobs will 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 and drop on the place 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 or four baby chickens.
 * Spawn Eggs are re-textured eggs with dots, colored similar to their respective mob, 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 (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. Naming sheep "jeb_" will make its wool color fade into all 16 colors of dyed sheep, although this will not affect the drops of the sheep.