What does the command `docker rm` do?

The command docker rm is specifically designed to remove stopped containers. When run, it cleans up space and ensures that stopped containers no longer consume system resources. This is an essential command for container management, as it allows users to maintain a clean environment by deleting containers that are no longer needed or have been replaced.

It is important to understand that docker rm does not affect running containers. In fact, attempting to use this command on a running container would result in an error unless the container is first stopped with a command like docker stop. This confirms its role in managing only stopped containers.

This functionality is critical during the development and testing cycles, as containers may frequently be created and destroyed, hence requiring an efficient way to remove those that are not active.