What does airgap mean?
An airgap is a physical gap of air that separates two things, most commonly encountered in two technical domains. In electrical engineering, it denotes the small space between a rotating part such as a rotor and a stationary part such as a stator in motors, generators, and transformers; the size of this gap directly affects efficiency and performance, so engineers control it precisely. In information security, an airgap refers to the complete physical isolation of a computer or network from the internet and other external connections, ensuring that no data can be transmitted wirelessly or through cabling. Systems protected this way are described as "air-gapped," and they are used where security is paramount, such as in military, industrial-control, and classified environments. The term conveys precision and rigor, and while specialized, it has gained wider recognition as awareness of cyber threats has grown.
nounA physical gap of air separating two conductors or components, especially in electrical machinery or transformers; more broadly, a physical isolation between a computer or network and the internet or other unsecured networks.
- In electrical engineering, the space between a magnetized component (such as a rotor) and its surrounding structure (such as a stator), critical to machine performance.
- In information security, a physical and logical isolation between a computer system and any external network, preventing remote access.
"The motor's rotor is separated from the stator by a narrow airgap that must be precisely maintained."
"Engineers carefully calibrated the airgap to minimize magnetic losses in the generator."
"Classified military networks are kept air-gapped so no data can leak over the internet."
The plural is rare outside technical literature discussing multiple machines or multiple isolation points.
"Different motor designs require different airgaps depending on their intended load."
The only computer hackers truly cannot reach remotely is one whose cables have been physically cut and unplugged — that's what an airgap is for.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of airgap
The word "airgap" is a straightforward English compound formed from "air" (ultimately from Latin via Old French) and "gap" (from Old Norse "gap," meaning a chasm or opening). It arose as a technical coinage within nineteenth- and twentieth-century electrical engineering, when precise terminology was needed for the clearance inside machines. Its later adoption in computing security extends the same idea metaphorically: a literal absence of connection.
How airgap is actually used
"Airgap" is primarily a technical term used by engineers and security professionals; in cybersecurity it often appears as the adjective "air-gapped" describing isolated systems.
Easily confused with airgap
"Airgate" is not an established English word; "airgap" specifically refers to a physical air separation in engineering or computing contexts.