Containerization is a way to package an application with the libraries, settings, and runtime it needs so it behaves more consistently across different systems. Instead of installing software directly on a host, teams run it in an isolated container that shares the host kernel but keeps the application environment separate. This makes deployments more portable across laptops, servers, private clouds, and public clouds.
In cyber security, containerization matters because it helps standardize builds, reduce configuration drift, and make systems easier to test, monitor, and patch. Defenders use containers to reproduce environments, segment services, and limit the impact of a compromise. Attackers also target containers by abusing weak images, exposed registries, misconfigured runtimes, or overprivileged containers. Good practice includes minimal images, signed artifacts, least privilege, and continuous scanning of container contents and orchestration settings.