Physical Representation of Boolean Values

“true” and “false” (1’s and 0’s) are physically represented by electrical voltages (low and high values).

0 volts represents:

• Logic-0
• false
• LOW / logical low
  5 volts represent
• Logic-1
• true
• HIGH / logical high

Low and high refer to the amount of voltage Logic-0 and Logic-1 refer to the engineer’s representation of 1’s and 0’s within circuits. These are equivalent to your true and false booleans!

Refer to Vcc and Ground $V_{cc}$ = logic high (5V’s) Ground = logic low (0V’s)

These give “context” for the rest of the circuit connected to them. I.e. the wire connected to ground has a “reference point” to 0V (and likewise for $V_{cc}$)

HOWEVER, if a wire is neither connected to ground or $V_{cc}$, it is said to not be connected to “anything” and does not have a “defined” voltage.