Taiko (太鼓?) means "drum" in Japanese (etymologically "great" or "wide drum"). Outside Japan, the word is often used to refer to any of the various Japanese drums (和太鼓,
wa-daiko, "Japanese drum", in Japanese) and to the relatively recent art-form of ensemble taiko drumming (sometimes called more specifically,
kumi-daiko (組太鼓)).
Japanese taiko drums have been developed into a wide range of percussion instruments that are used in both Japanese folk and classical musical traditions.
Taiko, in general, are stick percussion instruments. With the exception of the
kotsuzumi and
ootsuzumi, all taiko are struck with bachi. They have heads on both sides of the drum body, and a sealed resonating cavity. Taiko are also characterized by a high amount of tension on the drums heads, with a correspondingly high pitch relative to body size. This high tension likely developed in response to Japan's wet and humid summers when most festivals take place. Many taiko are not tunable, and a drum with high head tension would counteract the slacking effects of humidity.
Taiko are categorized into two types of construction.
Byou-uchi daiko (鋲撃ち太鼓, tacked-struck drum) taiko have heads nailed to the body.
Shime-daiko (締め太鼓, tightened drum), have heads sewn onto iron rings, which are then laced to each other around the drum body.
Byou-uchi daiko are typically hollowed out of a single piece of wood. The preferred wood is
keyaki (欅) due to its density and beautiful grain, but a number of other woods are used, grouped under the generic term
meari (目有). Byou-uchi daiko cannot be tuned, and their sizes are limited by the diameter of the tree they are made from.
Source:
Wikipedia 
