Describe the term- State Diagram

State Diagram: An object could receive a sequence of the input instructions. The state of the object can differ depending upon sequence of input instructions. If we draw diagram that will represent all processes (input) and their output (states) then that diagram is called as state diagram. Processes are represented by arrow symbol and states by oval symbol. For illustration, screen of an ATM machine has many states such as main screen state, process transaction state, request password state.