Kenjutsu techniques are those that imply the use of a sword or swords.Also while you can just use a sword,you can also enhance the power and damage dealt by the technique by combining kenjutsu with taijutsu,ninjutsu,chakra flow also in some rare cases genjutsu.Some of the best kenjutsu users are the Seven swordsman of the mist who have an unique sword each,Killer B who uses his unique multiple sword ken.And of course the Land of Iron solely relays on their samurai who only use kenjutsu to defend them.