...One state is active at any time, and UI-Router manages the transitions between the states. Each state describes the URL, the UI (a view or views), data prerequisites, and other logical prerequisites (such as authentication) for a feature. Before activating a state, UI-Router first fetches any prerequisites (asynchronously), and then activates the view(s) and updates the URL. UI-Router states are hierarchical; states can be nested inside other states, forming a tree. Child states may inherit data and behavior (such as authentication) from their parent states. ...