The katana is a type of Japanese long sword or backsword, curved and a single edge, traditionally used by the Japanese samurai, sometimes known as samurai sword.
The katana is generally defined as a standard size, moderately curved (compared to older usurpers with multiple curvatures) for Japanese swords with a blade length greater than 60.6 cm (23.86 in). It is characterized by its distinctive appearance: a curved, elongated, single-edged blade with a round or square guard (tsuba) and a long shank that accommodates two hands