- Docker images are basically a collection of filesystems
- One copy of an image of gets mounted to each container
- Images can be stored in a repository for use by other orgs
- Docker images can contain one or more filesystems
- Each filesystem in a docker image is called a layer
- The base layer is always the root filesystem
- When multiple layers exist in a docker image, the top layer will get priority
- When we create a container, all layers get merged into a single layer that gets attached to the container
- Docker images are stored in registries under the same name
- When docker containers are stopped, they do not reflect changes made to filesystem while running