Iaido is normally often mistaken as a part of kendo or kenjutsu but infact it is a totally different thing. Iaido is associated with the smooth and controlled movements of drawing the blade, with immediate reaction cutting an opponent and removing the blood before replacing the blade back into the scabbard.
Normally students or Iaidoka will use a shinken (unshapened blade) but there are also Dojos that use the real thing on their practices, while new students only uses a boken. The teachings are based on 90% of Katas, please do correct me if I’m wrong, the Katas can have up to a few imaginary opponents but there is no sparing or combative competition for Iaido.
It is quite hard to find a pure Iaido dojo, normally it is shared between Kendo or Akido and even it’s uniform are similliar which consists of Gi and Hakama.
Iaido is very much confused with kendo or kenjutsu and the difference for, Kendo is that kendokas are not taught the techniques of drawing and replacing blade back to it’s scabbard and also Kendo has sparing sessions as well as using Shinai, Boken and Metal Blade. Where else Kenjutsu are normally practiced with a partner in a form of Kata which is quite similar to Iaido except the partner part.
I really like the part of Japanese Martial Arts and the way they show respect to a lot of stuffs like the Dojo and your sparing partner, this image is a normal procedure that was practiced to show respect to the blade before and after practice.
Image Taken from: www.onlinedojo.ca