Container technologies package applications together with their dependencies in isolated environments. Docker is one of the most popular platforms that made containers widely adopted.

A common deployment problem is that an application works on a developer machine but fails on a server. Containers reduce this issue by packaging the runtime, dependencies and application together.

A Dockerfile defines how an application image is built. This image can then run as a container in different environments, providing consistency between development, testing and production.

Containers also play an important role in DevOps and CI/CD pipelines. Applications can be built, tested and deployed more reliably. However, security, image size and networking still require careful planning.