The CSS box model is a way of representing an element on a web page as a rectangular box. It allows you to control the width, height, padding, and borders of an element.
The box model in computer graphics consists of a bounding rectangle, contents of the rectangle, and a mesh. The bounding rectangle is a covelant object that defines the size and position of an object in 3D space while being completely independent from any rendering technique or more advanced physical simulation.
It provides for both scaling and placement of the element within individual digital environments. In this sense, it is considered to be one single rectangular entity where width, height, depth are all consistent with each other.
These properties represent only half the geometry needed for modeling an object because they encompass both position and scale but do not render anything on screen nor account for effects which would tend to distort or distort visual perception such as silhouettes.