The Cinema 4D Noise node is for using Cinema 4D's Noise shaders (figure 1). Recent versions of Octane added OSL versions of the Cinema 4D noises. The Octane Noise node is a native tool and very efficient. For speed and reliability, the Octane Noise node is the better first choice, with the Cinema 4D Noise node as a fallback as needed. More details on what the C4D Noise Shader is and what it does can be found in the Cinema 4D help documentation.
Figure 1: The Cinema 4D Noise node connected to the DiffuseAmount of diffusion, or the reflection of light photons at different angles from an uneven or granular surface. Used for dull, non-reflecting materials or mesh emitters. pin on a Diffuse Octane material