What does the command 'docker image prune -a' do?

The command 'docker image prune -a' is designed to help manage disk space by removing unused images from your Docker environment. When you use this command with the '-a' flag, it targets all images that are not currently being used by any containers, rather than only those that are dangling—meaning they are not associated with any tags.

This is particularly useful for reclaiming space because, over time, unused images can accumulate and take up significant space on your system. By executing this command, you clean up your Docker images, ensuring that only the ones actively in use by running containers are retained. This functionality is a significant aspect of Docker's resource management, enabling users to maintain a more efficient and organized development environment.