What Is an Image?

When we use docker run to start a container, we download a compressed, ready-to-use container called an image. Images make containers easy to share via a registry like Docker Hub, but also affect how file storage works when using containers.

In this tutorial, we'll:

  • Discuss how file storage works in Docker containers
  • Describe images, base images, and the scratch image
  • Identify layers and show how layers make up Docker's filesystem