||Iaido was formed only after World War II when a series of ten kata (~forms) were chosen, out of four koryu, called seitei kata.
Iaido is a way of defending and attacking with a real sword. You can see it as an equivalent of the cowboy’s fast gunfighting.
Iaido is most performed in kata in which attack and defence are prescribed. Because of the danger of injuries, iaido is practised single with a imaginary opponent. The sword was seen as the soul of the samurai and was therefore a sacred and very respectable weapon.