What Are Truth Tables and Boolean Logic?
Boolean logic is a logic system that works with only two values: true (1) and false (0). A truth table is a table that lists the output a logic expression or logic gate produces for every possible input.
What Is Boolean Logic?
Boolean logic is built on three basic operations: AND, OR and NOT. By combining 0s and 1s, these operations form the basis of digital decisions; they're directly related to the binary system.
What Is a Truth Table?
It shows the output of a logic expression for every possible input combination. A table for an expression with n inputs has 2ⁿ rows (2 inputs → 4 rows).
Example: 2-Input AND and OR
| A | B | A AND B | A OR B |
|---|---|---|---|
| 0 | 0 | 0 | 0 |
| 0 | 1 | 0 | 1 |
| 1 | 0 | 0 | 1 |
| 1 | 1 | 1 | 1 |
From Boolean Expression to Circuit
A condition is written as a Boolean expression (e.g. "light = dark AND motion"), then that expression is turned into a circuit with logic gates. A truth table is the most reliable way to check whether the circuit is built correctly.
Common Mistakes
- Wrong row count: n inputs need 2ⁿ rows; a missing row means a skipped combination.
- Confusing OR with XOR: in OR, 1 OR 1 = 1; in XOR, 1 XOR 1 = 0.
- Skipping precedence: NOT is applied before AND, and AND before OR (parentheses make it clear).
Frequently Asked Questions
Where is Boolean logic used?+
What is a truth table good for?+
Search related parts in our catalog
Find the right part by comparing price, stock and distributors.