An application container is a packaged software unit that runs an app in an isolated layer instead of directly on the host system. It bundles the application and the files, settings, and dependencies it needs, while limiting how much it can touch the rest of the operating system.
In cyber security, this isolation helps reduce application conflicts and can shrink the impact of a compromised or untrusted app. It is also useful for controlled software delivery: defenders can publish, update, or revoke apps without installing them loosely across endpoints. But containers are not a magic shield. If packaging, signing, or distribution rights are abused, attackers can push malicious code or alter trusted software at scale. Security teams therefore treat container templates, publishing systems, and update workflows as sensitive control points that need strong access control and change monitoring.