Google - Surfaces

It is easy to express space in the physical world as everything that exists’s in front of us has a sense of space. However, in the material environment, it is not easy to express space. This is because our phone and computers are basically 2D. But through the use of elements such as light and shadow, creates an illusion for the users.

Increasingly, as users spend more time in digital space, it has become important to provide better experiences for users. Actually, the principles described in the reading are all little details. Like this “Material Design has three-dimensional qualities that are reflected in its use of surfaces, depth, and shadows.” These properties aren’t simply for design aesthetics but provide context for the users.