In cybersecurity, 'air' commonly refers to an 'air-gapped' environment - a computer or network that is physically isolated from unsecured networks like the internet. This isolation prevents unauthorized access and protects sensitive data from remote cyberattacks. Air-gapped systems are often used in critical infrastructure, government, and military settings where security is paramount. They can be used to safely analyze potentially dangerous files or software, as the lack of external connectivity reduces the risk of malware spreading or data being exfiltrated.