Shade is the darkness of an object not in direct light, while shadows are the silhouette of an object’s shape on another surface. Created by the same light, shades and shadows react differently, and both influence how one perceives space, color, and feeling. Where shadows appear to have a constant color cast, shade can have a lessening intensity as light is diminished. The shading of a surface and the changing intensity brings out patterns and colors that transform throughout the day, helping to create a façade that can come alive. Creating motion in interior lighting is difficult, but these same principles are important to understanding its effect on the user as light can be bounced or grazed off surfaces.
https://mainehomedesign.com/design-theory/2467-shades-and-shadows/#close