Art of Sword : 
One weapon that stands out from almost all martial art and military training, is the sword.
In the Martial Science we have 3 specific ways that we teach the sword and each of these ways requires the use of a different sword. First you have a Bokken or wooden sword. Then you have a Shinai or bamboo sword and last you have a Katana or Real Sword. When learning to master the sword, it is important to have the right tools.

 Kenjutsu is a military art form which was created in Japan in the 15^th century. It was primarily designed to prepare samurai, as well as ordinary soldiers for combat on the battlefield. The main emphasis of kenjutsu centers around the practice of swordsmanship. But in some styles the practice of other battlefield-related weapons is also an integral part of their curricula. At the simplest level, it can be viewed as a collection of combat techniques for various weapons, most notably the sword. At a more complex level, it can be considered the study of the strategy both large-scale and small, offensive as well as defensive.

In terms of learning to fight with a sword, kenjutsu has a more complete curriculum. Kendo of necessity limits the range of techniques and targets. Kendoka generally use shinai, which allow techniques which do not work with real swords. Kenjutsu practitioners do not usually use shinai in training, preferring to use bokken (wooden swords) or katana (steel swords) in order to preserve the cutting techniques of real sword fighting. Kenjutsu training largely consists of practicing cutting technique and performing partner kata. For safety reasons, free-sparring is seldom practised with bokken or katana. 

It was natural for the samurais to practice everyday with their sword. To the samurai the sword was their foremost weapon and privilege - other groups in the society was forbidden to bear swords. Furthermore the practice with the sword was much more than preparing for battle. 
Around the japanese sword grew a whole philosophy. It has many names, as ken, katana, tachi, and to. 

KENDO:

is a sport with rules and conventions guiding acceptable targets, techniques, and scoring procedures

targets: wrists, head, throat, belly and sides of the waist

stance is upright, facing forward with the whole body, rear foot (left) slightly off the floor

main (most basic) cut is typically vertically straight down

weapon is a bamboo sword (shinai)

movement is predominantly linear

KENJUSTU:

is an art concerned with accurate and realistic sword technique applications, learning to fight with the sword in a real-life context

uses wooden swords, real swords, or bamboo swords, depending on the style.

targets are any targets of opportunity, but certain styles have preferences for specific targets like the head, wrists, etc.

grew out of the need for training samurai to fight on the battlefields and practical concerns of battlefield fighting.

stances, techniques, and tactics used depend on the particular style.

movements can be linear or circular or any combination of the two, depending on the style.

The study of swordsmanship improves one's skills of balance, coordination of mind and body, and increases awareness of detail. 

 Eye Contact
Where should your eyes be focused during combat? There are many different schools of thought on this question. The best advice is to look at the level of the solar plexus with Enzan no Metsuke, or Distant mountain site. This allows you to see the entire body all at once. If you watch only one portion of the body you can be fooled by a master swordsman. All parts of the body cannot fake a movement at the same time. 

Breath Control

When practicing kata, take three deep silent breathes attacking on the third breath. Think positive thoughts with each inhalation and disperse negative thoughts with every exhalation. The breaths should enter the nostrils, circle the crown of the head and settle to the Tan Tein. 
 
Iaido is the practice of sword techniques which embody a series of cutting and thrusting movements in the drawing and resheathing of the blade. These movements are performed against an imaginary opponent, and requires great concentration. 

"The essence of swordsmanship" lies in its perfection. 
It does not mean to cut the enemy, but rather to cut the enemy within oneself. 

The sword was thought to purify your spirit; the training became a kind of meditation in motion. A truly noble man handled his weapon with an entirely different style than the less noble, and the most noble thing would be if he never needed to draw his sword at all. All of the better samurais knew that to return victorious from a fight depended much more on your spiritual qualities than on your physical skills. The samurais´ training was much about being like the sword - pure, straight and sharp. 

In modern Kendo, there are two types of attacks: strikes and thrusts. Strikes are allowed to only three points on the body-the top of the head, the right and left sides of the waist and the forearms. Thrusts are usually permitted only to the throat. Unlike western fencing where two opponents show each other only their sides, in Kendo the opponents stand face to face and these four target areas were chosen because they are the most difficult. In competitive matches, it is not enough for your bamboo sword to just touch the opponent; points are awarded only when the attacks are done properly to the exact target with good control and a yell or Kiai. The first person to win two points wins the match. 

The Four Poisons

There are four deep-rooted mental or intellectual problems to be overcome in kendo. They are: fear, doubt, surprise, and confusion. These fears are known collectively as the "Four Poisons of Kendo".