Anair-gapped (C)system is completely isolated from unsecured networks (like the internet) and other systems, preventing any form of remote access. This is often used in highly sensitive environments such as military, nuclear, or critical infrastructure systems.

This is mentioned underDomain 3.4: Given a scenario, apply cybersecurity resilience conceptsin theCompTIA Security+ SY0-701 Exam Objectives, specifically under“Isolation (e.g., air-gapped)”.