What are the similarities and differences between artistic portrait photography and commercial portrait photography?

Both artistic portrait photography and commercial portrait photography are intended to be "a form of artistic photography that takes people as subjects and expresses the creator's thoughts or feelings", in order to obtain pleasant portraits and give people beautiful enjoyment. Pursuing aestheticism requires higher artistic accomplishment and higher technical skills than ordinary photography. Broadly speaking, commercial portrait photography should also be classified as artistic portrait photography. But from a functional point of view, commercial portrait photography ... "