What curvature type is the pcl::Normal class implementing?

I need to calculate the discrete mean curvature of each point of a point cloud. I was wondering if the curvature member of pcl::Normal is already the dmc as its calculated based on a search radius, or is it some other type? (e.g. discrete gaussian curvature) I couldn't find any information on that, would be rly grateful if someone could shed some light!