How can you exit a Docker container and affect the host system on which it is running?

To exit a Docker container and affect the host system, it's important to understand that containers are isolated from the host, but under certain conditions, access to the host can be gained:

• If the container is run with privileges (--privileged), commands affecting the host can be executed.
• If host directories are mounted into the container (via -v /host/path:/container/path), changes in these directories will reflect on the host.
• Docker CLI on the host can be used to manage containers.

For example, if the container has access to a mounted host directory /host_data, changes to files there will impact the host system.

Also, to exit the container, the usual key combination is Ctrl + P then Ctrl + Q — this detaches the terminal from the container, leaving it running. To stop the container, use the command docker stop <container_id> on the host.