3. Motion Principles
Motion in user interface is used to convey functionality, and intention with delight and fluidity. Great motion should support the user's orientation and act as a guide. It is used to establish hierarchy and draw the user’s attention to essential elements, giving them an understanding of an object’s role within the design. In order to convey this, the motion needs to be quick, direct, and precise.
Motion brings personality, tone, rhythm, and purpose to otherwise static objects. When applied properly, motion goes unnoticed. It should feel like a well choreographed dance, with all of the elements acting and reacting to one another simultaneously.