Indeterminate state for toggle buttons?

1. How many states are there while using a toggle switch?
2. Should a toggle button show its current state or the state to which it will change?
3. How do I know if my toggle is on or off?

How many states are there while using a toggle switch?

Toggle switch (known as “toggles”) is a UI control that has two mutually-exclusive states, such as ON and OFF. The design and functionality of this control is based on a physical switch that allows users to turn things ON or OFF (i.e. light switch).

Should a toggle button show its current state or the state to which it will change?

If you are just going to have one button to toggle between two states, then the button should represent the next state, because that is the action that the button will take when clicked.

How do I know if my toggle is on or off?

Toggle switches are white (when off) and green (when on).