Ninjutsu- Ninjutsu means "Ninja techniques" and it allows a person to perform techniques that they wouldn't be able to perform normally. It can be complexly manipulated in order to perform different tasks such as healing, shape transformation, and nature transformation. These techniques are fueled by chakra and hand seals can be used as a medium to help mold and manipulate chakra. Shape transformation deals with controlling the form, movement, and potency of chakra being harnessed. It is devastating by itself and can also be combined with nature transformation for a more devastating attack.
Elemental Ninjutsu- There are 5 basic elemental ninjutsu. Fire, water, earth, lightning, and wind. They require nature transformation which usually deals with changing the physical properties of chakra into a certain element. They all give different effects to jutsu when they are implemented.
Relationship- Cheating here and there but they are trying to work it out.
(Elemental Ninjutsu came from basic ninjutsu in an attempt to create new jutsu to be utilized in battle for offense, defense, or supplementary uses.)
Chakra- Chakra is essential for every technique (Except Tai). It is the moulding of physical energy, which is present in every cell of the body, and spiritual energy, gained from exercise and experience. Once moulded they can be channelled through the chakra circulatory system in the body, and used for all sorts of various jutsu.