Here the basic terms in the docker world that you should know.

A Docker image is the basic template for a Docker container.

An image usually contains the OS and applications that readily installed.

The Docker image is used to run the container, you can find many images with a variety of operating systems and software that has been installed in the Docker Hub https://hub.docker.com/.

Docker Container is an image which can be read and written to that runs on top of the Docker image.

Docker is using the union-file-system as backend for the container, any changes that are made in the container will be saved in a new layer above the base image.

The container is the layer where we install applications in. Each container that runs isolated in the host machine and therefore, provides a secure application platform.

Docker registry is a repository for Docker images.

It provides public and private repositories.

The public Docker registry is called the Docker Hub. Here we can push and pull our own images.