From a question to a circuit
Boolean logic treats a statement as one of two values: true or false. A computer represents those values physically with signal ranges that stand for 1 and 0. The exact voltages depend on the hardware, but the key is that a circuit can reliably distinguish the two ranges even when the signal is imperfect.
A logic gate applies a small rule to those values. An AND gate outputs true only when both inputs are true; an OR gate outputs true when at least one is; a NOT gate flips its input. Built from transistors, gates turn changes in electrical signals into decisions that can feed the next circuit.
Small rules, large computations
Consider checking whether a user may open a file. A system could combine “the user is signed in” and “the user has permission” with AND: access is allowed only if both conditions are true. More gates can test many conditions, compare values, or choose what a processor does next.
The same principle supports arithmetic. Circuits can combine gates to add binary numbers, detect whether two bit patterns match, and store results. A processor’s complex behavior is not one enormous yes-or-no question; it is a carefully arranged sequence of simple decisions, with each result helping determine the next.
Boolean logic is therefore a bridge between software instructions and electronic hardware. Programmers can describe conditions in readable terms, while circuits reduce them to signals that can be switched, combined, and acted on—one small decision at a time.
