Proportion

Proportion is the relationship of parts to each other and to the design as a whole. In this picture of a living room, each furniture is proportionally sized and placed to each other. Also, everything is proportionally spaced. For example, the paintings on the wall follow the 2/3 proportion rule in comparison to the couch.

Scale

Scale is the law of proportion when applied to the size relationship of objects used together. In this birds eye view of a living room, every furniture piece is sized well in comparison to each other. Nothing is too big or too small. By every furniture piece being to scale, it makes the room cohesive and nothing sticks out.