Answer:
the state of the circuit is a function of the voltage level. The interpretation is up to the user.
Explanation:
A binary digital circuit adopts one of two states, depending on whether the voltage level is above or below some threshold that depends on the design of the circuit. Within each state, the voltage may have some typical range. When the voltage is near the threshold, the state of the circuit may actually be "indeterminate".
The internal/output voltage is a function of the state of the circuit. The interpretation of that voltage as a true/false or 1/0 or other meaning is up to the user of the circuit.
The circuit interprets a given input voltage as intending to convey a particular input signal state according to the circuit specifications. Input voltages near the threshold between states may cause unexpected or even destructive results.
__
In order to conserve space, some digital circuits use more than 2 different voltage levels to signify more than 2 different states.
