Описание тега transitions

In Graphical User Interface ( gui) development, transitions are animations used to keep users oriented during user interface state changes and object manipulations, and make those changes feel smooth instead of jarring. Good transitions feel natural, often giving the illusion that users are interacting with real-world objects.

For state-machines, a transition is a progression from one state to another and will be triggered by an event that is either internal or external to the entity being modeled. For a class, transitions are typically the result of the invocation of an operation that causes an important change in state, although it is important to understand that not all method invocations will result in transitions. An action is something, in the case of a class it is an operation, that is invoked by/on the entity being modeled.