The katana and uchigatana are both types of traditional Japanese swords with similar appearances, but there are some notable differences between the two:

1. Blade Length: The most significant difference is the blade length. The katana typically has a longer blade, usually around 60-70 centimeters (24-28 inches). The uchigatana, on the other hand, has a slightly shorter blade, typically around 50-60 centimeters (20-24 inches). This difference in length affects the overall balance and handling of the swords.
2. Usage and Time Period: The katana is associated with the Edo period (17th to 19th century) and is considered the iconic sword of the samurai. It was primarily used for single combat, self-defense, and ceremonial purposes. The uchigatana, on the other hand, was used during the earlier periods, such as the Kamakura and Muromachi periods (12th to 16th century), and was designed for use on the battlefield.
3. Manufacturing Technique: The katana was often crafted using a more refined and intricate manufacturing process, with a focus on aesthetics and artistic value. The uchigatana, while still carefully made, typically had a simpler construction and was more utilitarian in nature.
4. Handle Design: The handle (tsuka) of the katana is usually longer than that of the uchigatana. This allows for a two-handed grip, providing better control and stability. The uchigatana, on the other hand, often had a shorter handle, allowing for more flexibility in grip and one-handed use.
5. Purpose and Function: The katana was designed as a versatile weapon suitable for various combat scenarios. Its longer blade and well-balanced design allowed for both slashing and thrusting techniques. The uchigatana, with its slightly shorter blade, was primarily used for cutting and slashing on the battlefield.

It's important to note that the terms "katana" and "uchigatana" can sometimes be used interchangeably or have slightly different interpretations depending on the historical period or region. However, these general differences help distinguish the two sword types in most contexts.