What is air-gapped and how does it improve network security

 An air gap is a network security measure that implies a physical separation between a secure network and any other computer or network. A gapped computer is not directly connected to the Internet, nor it is connected to any other system. 

Air gaps have been a common security measure in the critical infrastructure sector, where a cyber attack can disrupt or halt major operations. The systems that deploy gapping normally include:

Military computer systems and networks;

Governmental computer systems and networks;

Financial computer systems and networks;

Industrial control systems;

Nuclear power plants;

Aviation computers;

Medical equipment.

Gapped computers are typically located in secure places, such as in a separate server facility with tight security. As a precaution, air-gapped systems have restricted access, so only a few trusted users can access them.

Types of air gaps

There are three main types of the air gap concept. Let’s see each type in more detail.

Total physical air gaps: this type assumes complete physical separation of a system/device from the network. That means there are no network connections to the device and if you need to get or load the data onto it, you need to go to the storage place directly. You may also need to pass through the security since physical access to the environment where the device is stored is usually restricted. 

Isolated air-gapped systems: this type implies that systems/devices are not connected to a common network, but are in the same place (i.e. in one room).

Logical air gaps: are not separated physically from the rest of the system but are isolated from it through encryption and hashing. references:

https://softteco.com/blog/what-is-air-gap