# Knowledge Check: Docker CLI

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**1. What's the real difference between `docker run` and `docker exec`?**

*Answer:* `docker run` always creates a brand-new container from an image. `docker exec` runs a
new command inside an ALREADY-running container — no new container is created.

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**2. Which command is the container-level equivalent of ROOT 02's "what's running" question
(`ps aux` / service inspection)?**

*Answer:* `docker ps` (add `-a` to include stopped containers too).

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**3. Why doesn't `docker logs` require you to know a specific log file path, unlike a
traditional Linux service?**

*Answer:* Docker automatically captures a container's stdout/stderr output — there's no
separate log file configuration needed the way ROOT 02's services required.

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**4. What does `docker stop` actually send to a container's main process, and why does that
matter?**

*Answer:* SIGTERM first (a polite shutdown request, giving the process a chance to clean up),
then SIGKILL after a grace period if it hasn't exited — the exact same signal discipline ROOT 01
taught for regular Linux processes, applied here to a container's main process.

## Instructor Notes

**Facilitation:** Question 1 is the single most important check in this module — revisit the
demo if students get it wrong.

**Approximate timing:** 5 minutes.