Things to know about Docker

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