Chakra is essential to even the most basic technique in the Naruto series; it is the molding of the physical energy present in every cell of the body and the spiritual energy gained from the mind. Once molded, it can be channeled through the chakra pathway system, which is to chakra as the circulatory system is to blood, to any of the 361 tenketsu in the body. Through various methods, the most common of which is hand seals, the chakra can then be controlled and manipulated to create an effect that would not be possible otherwise, such as walking on water, exhaling fire or creating illusions.
Through the process of nature transformation, chakra can be converted into a number of different natures. Most ninja have a natural affinity to one chakra nature, but they have the capacity to use natures apart from their own affinity. There are five basic natures, but in addition to these, certain genetic traits allow multiple natures to be combined into new natures; for example, it is possible to mix Water and Wind Style into Ice. While many ninja can use more than one chakra nature, very few are able to combine them in this manner.