The terms "daito" and "katana" are often used interchangeably, but technically they refer to different lengths of Japanese swords.

1. Daito: The term "daito" (大刀) translates to "long sword" in Japanese. It generally refers to any Japanese sword with a blade length of over two shaku (approximately 60.6 cm or 23.9 inches). Daito can include various types of long swords, including tachi, odachi, and nodachi.
2. Katana: The term "katana" (刀) specifically refers to a type of single-edged, curved sword with a blade length of approximately 60 cm (23.6 inches) or longer. Katana blades are typically worn with the cutting edge facing up and are renowned for their craftsmanship and significance in Japanese swordsmanship.

In summary, a katana is a specific type of Japanese sword with a curved blade and a length that falls within the range of a daito. While daito can include various types of long swords, the katana has become one of the most iconic and widely recognized Japanese swords in popular culture and history.