Sometimes we need to apply a state in some cases when we want to modify a status of an object. A basic example is water state: gaseous, liquid and solid and the events responsible for change it:
Object: Water Event: Fusion States: From solid to liquid Event: Evaporation States: From liquid to gaseous Event: Condensation States: From gaseous to liquid Event: Solidification States: From liquid to solid
Look at this as a simple example that happens around us. As in many other cases, we can apply it in programming using something called state machine.
In the above example, we have different states and events responsible for change these states.
pending are possible states for a object and the state of an object can change when an event occurs. Pretty similar to the example of water states, right?