Throughout this chapter, we have been cleaning up our environment by running the docker-compose down command, which stops and destroys any containers associated with the todobackend Docker Compose environment.
One other aspect of housekeeping that you need to be aware of when building Docker images is the concept of orphaned or dangling images, which are images that have been superseded by a newer build. You can get a sense of this by running the docker images command, and I have indicated which images are dangling in bold:
> docker imagesREPOSITORY TAG IMAGE ID CREATED SIZEtodobackend_app latest ca3e62e168f2 13 minutes ago 137MBtodobackend_migrate latest ca3e62e168f2 13 minutes ago 137MBtodobackend_release ...