An iaito is a training sword specifically designed for the practice of iaido. While an iaito may resemble a katana in appearance, there are some important differences between the two.

1. Construction: A katana is a fully functional and sharp sword, typically made of high-quality steel. In contrast, an iaito is a non-sharpened practice sword. It is usually constructed with a blade made of aluminum alloy or zinc-aluminum alloy, which provides the necessary weight and balance for training but eliminates the risk of accidental injury.
2. Blade Edge: A katana has a sharp cutting edge, designed for use in combat or for practical purposes. In contrast, an iaito has a blunt or rounded edge, ensuring safety during practice while still allowing practitioners to perform the required cutting techniques without risk of injury.
3. Training Purpose: The katana is a functional weapon historically used by samurai in combat. The iaito, on the other hand, is a dedicated training tool used specifically for iaido practice. It allows practitioners to perform the various drawing, cutting, and resheathing techniques without the danger associated with a sharp blade.
4. Legal Considerations: In many countries, possession and use of sharp swords, such as a katana, may be subject to legal restrictions. However, iaito swords are typically not subject to the same legal regulations since they are not sharp and are primarily intended for training and practice.

Overall, while an iaito resembles a katana in appearance, it serves a distinct purpose as a practice sword for iaido. It provides practitioners with a safe and suitable tool to train and refine their techniques without the risks associated with a sharp blade.