Process isolation is the practice of separating workloads so one process cannot easily observe, influence, or damage another. In operating systems, this usually means giving each process its own boundaries for memory, files, devices, privileges, and sometimes even network access. Strong isolation reduces the blast radius of bugs, unsafe input handling, and compromised services.
In cyber security, process isolation is a core defense behind sandboxes, containers, and least-privilege service design. Linux mount namespaces and bind mounts, for example, can make a process see only a controlled filesystem view, while permissions and MAC policies limit what it can touch. Attackers try to break isolation by escaping sandboxes, exploiting misconfigured mounts, abusing shared resources, or reaching a privileged parent process. Defenders rely on isolation to contain malicious code, but it works best when combined with strict access control, careful configuration, and runtime hardening.