What is the difference between `docker-compose` commands `down`, `kill` and `stop`?

As documentation of docker-compose says:

• docker-compose down stops containers and removes containers, networks, volumes, and images created by docker-compose up,
• docker-compose kill forces running containers to stop by sending a SIGKILL signal,
• docker-compose stop stops running containers without removing them, so they can be started again with docker-compose start.

So, if you can wait for a while, and you want to do a simple, "hot" restart, without removing or disabling Docker infrastructure elements (like containers or networks), you should use docker-compose stop. This is the least invasive option.

If you hurry up, and you don't want to wait for a graceful stop operation, but you also don't want to remove containers, you should use docker-compose kill. The container stops working, but it is ready to be started again.

And if you are not interested in preserving containers at all, you can use docker-compose down. This scenario is a kind of "cold" restart.

Note that you can also use docker-compose pause, which pauses running containers of service, so they are not stopped (like in the command mentioned above), and they can be unpaused with docker-compose unpause.

From Gerad answer, if you consider a container as running OS (e.g. Windows) those commands can be mapped to:

• pause (unpause) -> hibernate
• kill -> soft shut-down
• stop (start,restart) -> hard shut-down (by unplugging the system)
• down (up,create) -> factory reset