A separation method is a technique for isolating one material, process, or data set from another so they do not mix. In cyber security, the same idea appears as isolation: keeping sensitive systems, credentials, or traffic apart from untrusted components. Common examples include network segmentation, sandboxing, container isolation, privilege separation, and air-gapped systems.
Separation matters because many attacks succeed when boundaries break down. If an attacker can move from a low-trust area into a high-trust one, they may steal data, run code, or reach critical services. Defenders use separation to limit blast radius, reduce lateral movement, and make compromise harder to spread. Strong separation is not absolute protection, but it is a core control for containing risk and enforcing trust boundaries.