The Triplanar Projection works with a Triplanar Texture node. It takes the coordinates in world or object space and picks the projection axis depending on the Triplanar node's active axis. This gives a quick way to map a texture on any object, and presents the possibility for texture transforms local to each projection axis.
While the Triplanar Texture node maps the samples of multiple textures along three planes (x, y, and z), the Triplanar Projection node localizes the texture's projection and allows better transform control on a particular plane.
Figure 1: The Triplanar Projection node used to provide more control over scale and rotation edits provided by the Transform 3D node