Iaido is a discipline of Japanese swordsmanship. It is a non-combative physical and mental discipline based on a prescribed use of the traditional Japanese sword. Students train individually and are taught the techniques of drawing, cutting with and returning the Japanese training sword known as an iaito (a dull-bladed practice sword) to its scabbard.
An excellent book to learn more about Iaido is "Japanese Swordsmanship" by Gordon Warner and Donn F. Draeger.