Understanding the Lifecycle

This visualizer demonstrates the primary workflow of Docker.

1. Dockerfile (Source)

The Dockerfile is your recipe. It defines exactly what goes into your environment (OS, dependencies, environment variables).

2. Image (Build)

The Image is your packaged product. It’s unchangeable (immutable) and can be shared on Docker Hub. If you change your code, you build a new image.

3. Container (Run)

The Container is the running process. You can start, stop, and delete containers. You can even run many containers from the same image simultaneously.

4. Running App (Exposure)

By default, containers are isolated. You must explicitly “expose” or map ports to let traffic reach your app.