Before using the docker stop command can be used to stop a container, you will probably want to use the docker ps command to determine if the container is running. In this example, the bar container has been running for 12 hours.

~]# docker ps -a
CONTAINER ID   IMAGE         COMMAND                  CREATED        STATUS                    PORTS     NAMES
d7bf9e534d50   foo           "/docker-entrypoint.…"   12 hours ago   Up 12 hours               80/tcp    bar

A Docker image contains the code used to create a Docker container, such as creating a Nginx web server, or a mySQL server, or a home grown app, and the list goes on. In this way, an image is like a template used to create a container. An image is kind of like a virtual machine, but much more light weight, using significantly less storage a memory (containers are usually megabytes in size).

The docker stop command with the container name can be used.

docker stop bar

Or with the container ID.

docker stop d7bf9e534d50