The === operator (strict equality operator) compares both values and types for equality. It returns true only if the operands have the same value and are of the same type. For example, 5 === 5 returns true, but 5 === '5' returns false because the types are different (number vs string). This is different from the == operator (loose equality), which performs type coercion before comparison, so 5 == '5' would return true.