Fundamental logic gates — complementation behavior: For which logic gate is the output always the Boolean complement (inverse) of the single input?

Introduction / Context:
Digital systems are built from basic logic gates. The NOT gate (also called an inverter) performs the essential operation of complementation: converting logic 1 to logic 0 and vice versa. Recognizing which gate provides inversion is foundational for analyzing and designing combinational circuits.

Given Data / Assumptions:

• Single-input gate behavior is under consideration.
• We seek the gate whose output is the complement of the input.
• Standard Boolean algebra conventions apply (0 ↔ 1 inversion).

Concept / Approach:
The NOT gate outputs Y = X’, where X’ denotes the logical complement of X. Multi-input gates like AND and OR compute different Boolean operations; XOR (exclusive-OR) compares two inputs to produce 1 when inputs differ, not the simple inversion of one input in general.

Step-by-Step Solution:
List gate behaviors: NOT inverts; AND and OR combine inputs; XOR is inequality of two inputs.Match “complement of the input” with inverter behavior.Select NOT (inverter) as the correct gate.

Verification / Alternative check:
Truth table for NOT: X=0 → Y=1; X=1 → Y=0. This directly matches the requirement.

Why Other Options Are Wrong:
AND/OR are aggregation functions; XOR requires two inputs and is not a simple complement of one input.

Common Pitfalls:
Misreading XOR as inversion; XOR with one input tied high behaves as NOT on the other, but that is a special case, not the definition.

Final Answer:
NOT.