Door

A Door is a block obtainable through crafting and found in NPC Villages and Strongholds. Doors come in two varieties: wooden doors made from planks, and iron doors made from iron ingots. Doors are hinged at a corner and have two states: rotated clockwise and rotated counter-clockwise. Villagers are the only mob that can open doors without any redstone-based help, although zombies can destroy wooden doors when the difficulty is set to hard.

The sound of opening and closing of a door can be heard up to 16 blocks away, like mob sounds with the exception of the Ghasts.

Fluids cannot flow through doors, open or closed.

Wooden Doors
A Wooden Door using right mouse button will shift from one state to another state allowing or preventing passage. Players used to be able to also open wooden doors by left clicking as well, but that has been changed as of the 1.4.2 Pretty Scary Update. They may also be opened by using levers, buttons, pressure plates, or redstone.

Since zombies will only pound on or attempt to break down a Wooden Door when it is shut, any door placed so that its open state prevents passage, zombies will be unable to break down the door. This method is useful for protecting villages or the home of the player.

Iron Doors
An Iron Door is only able to be toggled by a switching mechanism. Iron doors can take quite a bit of time to destroy, even with a pickaxe. To destroy them more quickly, simply break the block beneath the door. Builders can discourage this by placing lava at the top of a 1x1 shaft above the door, and/or by placing the door on top of an obsidian block (or bedrock, if you are in creative mode.)

Since villagers cannot operate buttons or levers and zombies cannot break them, iron doors can be used to lock a house in a generated village.

Double Doors
If two doors are placed adjacent to each other, they will orient with their handles inward, creating a double door. Double doors can be opened by simply placing two pressure plates directly in front of the doors and stepping on them. Each pressure plate will open its respective door, and activating both pressure plates will open both doors.

Boats can also pass through double doors, with the doors acting as locks on canals or docks.

Bugs

 * If you manage to close a door on yourself and be caught inside it, when you log out and log back in, you will spawn back in on top of the structure in which the door is located.
 * You can get stuck in between the door and go one of 2 ways: Back inside or outside.
 * If you shoot an arrow at a door, and open it, the arrow floats in the air.
 * When a zombie attacks a door, the pattern appears that shows that the door is being broken. If you break the door before the zombie does, the pattern will stay floating in the air where the door was.
 * Sometimes, you can place a block through a closed door.
 * In creative mode, if there's a fire in a house on the wall next to the one with the door, the top half of the door will sometimes disappear.
 * As of version 1.3.2, you can not place a door directly in front of a solid block.
 * In Pocket Edition, you can sometimes place blocks on the other side of the door when attempting to open it.
 * In Pocket Edition, if you place a door on unavailable blocks(like stairs or slabs) it will spawn another door.
 * When you power any type of door with a redstone torch then break the door and replace it where it was before, the door will not be activated by the redstone torch as if the redstone torch wasn't there.
 * In survival, if a hostile mob such as a Creeper is right behind a door so the player is in the Creeper's line of vision, it will still glance at the player in a non-hostile way, but will not engage the player.
 * Hacking any type of door into your inventory via data values, Only the bottom block of the door will be spawned in. This glitched "half-door" will break and drop as a regular door when a block next to it updates. This may be used for one-time BUD switches for custom maps or for traps concerning TNT.

Trivia

 * In Pocket Edition, standing in the center of a door will mean that you can punch blocks on the other side of the door without any interference.
 * Despite being made of wood, Wooden Doors do not catch fire.
 * Doors placed underwater can be used as air pockets.
 * If a waterflow passing an opened wooden door is stopped, the door will close.
 * Minecarts can drop through doors if the door is in the right state (open/closed). This is an effective way to control them.
 * If you stand in an open door, then close it, you don't collide until you walk out and back in.
 * While aiming at one half of the door while opening or closing it, if you are positioned in such a way that you are aiming at the opposite half of the door after the door has changed its state, it will open and close until you release the hit/use-key.
 * It is impossible to place doors on an ice block.
 * In SMP, pressure plate lag may cause the server to drag you back behind a closed door when you thought you had already exited.
 * If you manage to be in the door by closing/opening it a few times while being really close to the door can make you jump on the bottom side of it, and if you jump again, being on top of the side door.
 * Placing the door inside out in your home will mean that monsters will be able to attack you through it. You should place the door safely by going outside of your home, and then placing the door in the doorway that you have made. (See the beginner's tutorial)
 * Breaking something next to a door will cause it to shut.
 * If you harvest the back side of a door, you'll notice the harvesting animation is mirrored.