This figure is two views of the same item; a “top” view and an “elevation” view. The top figure shows a large sphere labeled, “Moral Sphere” which encompasses the smaller sphere labeled, “Ethical Sphere”. If you look at the world through a Moralistic lens, you may see ethics as part of morality. This would be understandable since ethical matters overlap moral matters which is why the two have been viewed as synonymous historically.
The bottom figure provides an elevation view of the top view and is used to illustrate an important point; ethics and morality are different because they are knowable through different means. Morality is knowable through culture, where as ethics is inherently knowable. Morality is inherently relativist, ethics is inherently universal. While they seemly overlap they are knowable through different means. Proper understanding of ethics requires one understand the distinction between the two.