Logic gate
In the Off state, the voltage is at zero. The On state usually uses a voltage in the range of 3.5 to 5 volts. This range can be lower for some uses. A logic gate is 'on' or active when its rules are correctly met. At this time, electricity is flowing through the gate and the voltage at its output is at the level of its On state. Logic gates are electronic versions of Boolean logic. Truth tables will tell you what the output will be, depending on the inputs.