Tameshigiri is cutting practice with the Japanese sword. From a classical perspective it is a part of the kenjutsu curriculum so that the student confirms that their cutting motions are correct and acquires actual experience in using the sword to cut. In modern application the primary targets are soaked goza and bamboo.
Proper application of the sword in cutting teaches practical function.
The student learns how much pressure to apply to cut different
objects, rapid multiple cutting with proper angle of attack
of the blade and controlled follow through, and how impact
affects the blade. Mental concentration is improved and at
higher levels of skill and understanding the student comes
to realize that it is the mind that does the cutting.