In the context of Iaido, an Iaido sword refers to a specific type of Japanese sword that is used for training and practice in the martial art of Iaido. The Iaido sword is often referred to as an "Iaito" or "Iaido training sword."

The Iaido sword closely resembles a traditional Japanese katana in terms of its shape and design. However, there are some key differences:

1. Blade: The blade of an Iaido sword is typically made of aluminum alloy or zinc-aluminum alloy. It is unsharpened and does not have a cutting edge. This is done to prioritize safety during training while still maintaining the weight and balance of a real sword.
2. Construction: Iaido swords are often made as one-piece constructions, with the blade and hilt (tsuka) forged together. This differs from traditional katana, which have a separate blade and handle.
3. Weight: Iaido swords are generally lighter than real swords, allowing practitioners to perform techniques with ease and precision during training.
4. Saya (Scabbard): The scabbard of an Iaido sword is typically made of lightweight materials such as wood or resin. It is designed to fit the blade securely and to protect it when not in use.

The purpose of the Iaido sword is to provide practitioners with a safe and suitable training tool for practicing the drawing, cutting, and sheathing techniques of Iaido. It allows students to focus on the proper form, control, and movements without the risks associated with using a sharp, live blade.