Ninjutsu techniques

An example of ninjutsu.

Ninjutsu (忍術; Literally meaning "Ninja Techniques") refers to any technique that utilises chakra and allows the user to perform actions that a normal person otherwise would be incapable of doing.

Unlike genjutsu, which causes the opponent to experience illusions, the effects of ninjutsu are actual and physical in most cases. Ninjutsu relies on chakra and, most of the time, hand seals to be effective.

The hands are put in sequential positions that moulds and manipulates chakra in the necessary manner to perform a jutsu. This is not always needed, however, and some jutsu become second nature to experienced ninja, after which they can perform them at will. Additionally, many ninjutsu can be classified as an elemental jutsu, in those cases where a specific element (wind, water, fire, earth, or lightning) is used.

When creating a ninjutsu, the two methods of manipulating chakra are referred to as Shape Transformation and Nature Transformation :

An example of shape and nature
manipulation combined.

- Shape Transformation deals with controlling the form, movement, and potency of chakra.

- Nature Transformation usually deals with changing the physical properties of chakra into an element.
(There is also the Nature Transformation of Yin and Yang, but little is revealed about this)

These two methods can be implemented separately or together in order to create a ninjutsu.

It is said that the Sage of the Six Paths was the first to explain the mysteries of chakra, traveling throughout the world to spread his ideas and religion, the Ninshū (忍宗, Shinobi Sect).

The teachings were meant to give people a better understanding of themselves, as well as others, and lead the world into an era of peace. However, as time wore on, ninshū would eventually come to be known as ninjutsu, a more weaponised version of the Sage's teachings.

It can be used in collaboration with taijutsu to create nintaijutsu techniques.

source from : [naruto.wikia.com]