Normal bump mapping is a way of adding high-resolution detail to low-polygon objects. It is especially useful for real-time display devices such as game engines, and it can also be used in rendered scenes and animations.
A normals map is a three-color map, unlike the grayscale maps used for regular bump mapping. The red channel encodes the left-right axis of normal orientation, the green channel encodes the up-down axis of normal orientation, and the blue channel encodes vertical depth.
Remember... When something is ‘new and improved!’ which is it? If it’s new, then there has never been anything before it. If it’s an improvement, then there must have been something before it.