A container is a lightweight, isolated environment for running software that packages code and all its dependencies together. Unlike a full virtual machine, a container shares the host operating system kernel but has its own file system, processes, and network namespaces. Containers make it easier to run the same application consistently across development, testing, and production. Tools like Docker allow developers to build, run, and distribute containers using images stored in registries. Containers have become a core building block of modern cloud computing and DevOps workflows.
key characteristics
Containers start quickly and use fewer resources than full virtual machines because they reuse the host OS. Each container is built from an image that describes the file system contents and startup command. Container platforms provide networking so containers can talk to each other over virtual ports and network protocols. Orchestrators such as Kubernetes manage scaling, rolling updates, and resilience for groups of containers. While containers isolate processes, they still require careful configuration and firewall rules to be secure. When working with AI on deployment questions, specifying that an app runs in containers helps the AI choose realistic patterns and tools.