Katana is a type of Japanese backsword or longsword.
In use after the 1400s, the Katana is a curved,
single-edged sword traditionally used by the samurai.

Pronounced[kah-tah-nah] in the kun'yomi (Japanese reading) of the kanji, the
word has been adopted as a loan word by the English language; as
Japanese does not have separate plural and singular forms, both
"katanas" and "katana" are considered acceptable plural forms in
English.

The katana was typically paired with the wakizashi or shoto, a similarly
made but shorter sword, both worn by the members of the warrior class.
It could also be worn with the tanto, an even smaller similarly shaped
blade.

The two weapons together were called the daisho, and represented
the social power and personal honour of the samurai. The long blade was
used for open combat, while the shorter blade was considered a side arm,
more suited for stabbing, close quarters combat, decapitating beaten
opponents when taking heads on the battlefield, and seppuku, a form of
ritual suicide.

Japanese swords are fairly common today, antique and even modern forged
swords can still be found and purchased. Modern nihonto or Japanese-made
swords are only made by a few hundred smiths in Japan today at contests
hosted by the All Japan Swordsmiths Association.