A computer network with no physical or wireless connection to the internet or to any other network that is not equally secured.
An air-gapped environment is the strictest form of network isolation: even the ordinary corporate network has no route into it.
The name refers to the empty space between the protected system and every other network, with no cable or radio link crossing it. Moving data across that gap is a deliberate physical act: cleared staff carry it over on approved, encrypted media, and every transfer is controlled.
For AI, running models in an air-gapped environment provides strong protection against cyber espionage, data exfiltration, and external zero-day exploits.
See also Data Exfiltration, Role-Based Access Control and Zero Trust Architecture.