Named for the exterior, chitinous wings of beetles, the elytra is the single most desirable and rarest item in Minecraft at the time of this writeup. In simplest terms, the elytra is a cape the player avatar can wear, which grants the power of flight in the game's Survival Mode (though in Creative Mode flight is already an ordinary capability of the avatar).
Under normal circumstances, the elytra only actually enables gliding, at a 10/1 ratio of distance traveled horizontally to vertical drop, on a 0° glide path. More speed can be obtained by tilting the flight path downward somewhat to 5.9°, with the maximum gliding speed reached at 52° angled downward (which enables an equivalent ground speed of 69.5 blocks per second, but also forces the player to land very quickly). True flight is obtainable through the use of firework rockets, which act as a source of thrust, making the combined elytra and firework rockets act as a jetpack for the player.
Unlike most items in the game, the elytra is not obtained either by crafting it from other materials at a Crafting Bench, nor by slaying mobs in order to retrieve it as a dropped item. The actual process for obtaining an elytra requires first accomplishing a long consecutive sequence of increasingly difficult achievements within the game, each of which is fundamentally necessary to reach the next step. The final step of this process is to visit an End Ship in the realm of the game known as the End, and there to slay a monster called a Shulker, which is guarding a picture frame on a wall of the ship. This frame has the elytra contained inside it, and once it is obtained, it can immediately be equipped by the player and used to make a hasty escape from the End, reducing the risk of accidentally dying before getting safely back to the game's Overworld with the elytra.
The elytra is equipped as armour rather than a held item, and it is placed in the slot of the player's inventory that normally holds a chestplate. The elytra does suffer the same decrease in its durability over time as it is used, as other tools and armour suffer. An elytra normally only has a bit more than seven minutes of total consecutive use before it becomes unusable, but enchantments can be placed on it by the player, to increase that duration to about twenty-eight minutes. Unlike other items, the elytra does not fully despawn when its durability runs out: it simply desists in supplying gliding power, and the player is later able to repair the elytra at an anvil by combining it with phantom membranes, a mob drop produced by an aerial monster.
The word "elytra" is plural of singular "elytron," but for the purposes of Minecraft, players generally call this item "an elytra" rather than "a pair of elytra." There is no item in the game equivalent to a single elytron.
Some large-population Minecraft servers, such as reddit's p.nerd.nu player-versus-environment server, use game mods to mass-produce elytra which players can then purchase with other materials they have gathered on the server. This is done to improve quality of play for all players, especially those who arrive later in the server's lifespan: under normal circumstances, the number of elytra in the game is finite, and only the most skilled players earliest to arrive would have any chance at obtaining one, preventing later players from getting to glide and fly.
Iron Noder 2018, 24/30