View states let you vary the content and appearance of a component or application, typically in response to a user action. For example, the base, or default, view state of the application could be the home page and include a logo, a sidebar, and some welcome content. When the user clicks a button in the sidebar, the application dynamically changes its appearance, meaning its view state, by replacing the main content area with a purchase order form but leaving the logo and sidebar in place.
Transitions define how a change of view state looks as it occurs on the screen. For information on transitions, see Using Transitions.