Hopper

The hopper is a block which, when placed, will attach to the face of the block the player is facing. If an item falls into the top of it, it will store it in its own internal inventory of five item slots. However, if the block the hopper is attached to is a container with inventory slots (like a chest or another hopper), the hopper will transfer items from its inventory to the inventory of the attached block at rate of about 2-3 items per second. The hopper will also transfer items from the inventory of a container placed above it into its own inventory at the same rate. If the hopper is both drawing items from a container above it and also putting them into a container beside or below it, it will alternate between the two containers, effectively transferring items between the containers at 1-1 1/2 items per second.

Hoppers can not currently be used for automating furnaces. When fuel and smeltable items are fed into the furnace, they are not always placed in the correct slot. Also, if a hopper is placed underneath the furnace, it will take items from all of the furnace's slots, rather than just the output, removing items before they have a chance to smelt.

Rails can be placed on Hoppers using shift-click and the Hopper will suck items through the rails out of a Minecart with Chest. This is useful for making stations.

Bugs

 * Sometimes, hoppers will not connect to chests sideways. [This bug is only effective on some versions. It can be fixed by placing a hopper into the direction you want it to go to, as hoppers do not automatically connect]
 * Sometimes when a tool or item that can't stack is dropped on the hopper, the item will remain on top of the hopper and copy the item while still transferring the item until it fills the hopper slots or the connected chest
 * When you drop items on the hopper, if they land on the side, they will not get sucked in the hopper but make infinite copies of themselves in the hoppers until they are retrieved or fall in the hopper or despawn.

Trivia

 * A hopper is a type of chute used in industrial processes that incorporates a limited storage capacity.
 * Hoppers will not connect to Ender Chests.
 * Currently, hoppers do not automatically connect to the nearest storage block. Instead, you must place it against the storage block by holding shift and right clicking.
 * The texture of the hopper, especially its top, is clearly a derivative texture of the cauldron
 * The hopper used to load items into ordinary minecarts and powered minecarts. This was fixed in snapshot 13w01b.

Gallery
Trichterblock Embudo Entonnoir 漏斗 Загрузочная воронка