The chokuto and the katana are both traditional Japanese swords, but they differ in terms of their design, blade shape, historical usage, and time period. Here are the main differences between the two:

1. Blade Shape: The chokuto is characterized by a straight blade, similar to a straight sword found in other cultures. It lacks the distinctive curve that is associated with Japanese swords like the katana. In contrast, the katana has a curved, single-edged blade with a gentle curve. The curve of the katana allows for more effective slashing and cutting motions.
2. Design Evolution: The chokuto is an ancient style of sword that dates back to Japan's early periods, such as the Kofun and Asuka periods (3rd to 7th centuries). It was one of the earliest forms of Japanese swords, with a straight blade influenced by Chinese sword designs. The katana, on the other hand, evolved over time from earlier curved swords like the tachi, gaining popularity during the Muromachi period (14th to 16th centuries) and reaching its peak during the Edo period (17th to 19th centuries).
3. Historical Usage: The chokuto was primarily used during ancient times in Japan, when battles and warfare had different styles and tactics. It was the sword of choice during the Kofun and Asuka periods, associated with the samurai class of that era. However, as Japan entered the Heian period (9th to 12th centuries), curved swords like the tachi and later the katana became more prevalent due to changes in armor and battlefield tactics. The katana became the primary sword used by samurai during the feudal era.
4. Functional Differences: The chokuto was primarily designed for thrusting and stabbing motions, reflecting the combat styles of its time. The straight blade was effective for penetrating armor and targeting vital areas. In contrast, the katana was developed with a curved blade to enhance cutting ability. Its design allowed for swift, controlled strikes and efficient slashing techniques on the battlefield.

It's important to note that the chokuto is an ancient sword style and is not commonly used or produced in modern times. The katana, on the other hand, retains its popularity and is revered as a symbol of traditional Japanese craftsmanship.

In summary, the chokuto is an ancient straight sword style used in early periods of Japanese history, while the katana is a curved sword that evolved from earlier designs and became the iconic sword of the samurai during the feudal era. The chokuto is primarily associated with thrusting, while the katana is renowned for its cutting ability.