The term “air gap” does not directly imply anything to do with the Internet (doesn’t exclude it, but it applies more generally than specific networks). Yes, IC uses it to signify high/low networks, but the original usage of the term was to indicate a machine with no direct connection to the outside world. The theory being (since proven wrong), you can’t exfiltrate data remotely from a device not connected to a network.

What if it’s submerged in coolant?