Shape Transformation

Form Transformation changes the shape and movement of chakra. Various shapes and/or movements of chakra create different effects when used. Rasengan, for example, is in a shape of a sphere, the movement of chakra is spiraling around. When used, the chakra turns in a spiral formation, like a hurricane or a typhoon.

Combining with Nature Transformation
While Form Transformation changes the shape and movement of chakra, Nature Transformation changes the actual nature of the chakra, altering its properties and characteristics. Because of this, a technique like Rasengan can be turned into Wind Release: Rasengan or Wind Release: Rasenshuriken, because of Wind Release being joined withe the movement of chakra. The movement, instead of spiraling, turns into millions of minuscule lines, as seen when used against Kakuzu.