A Docker image is a template for a container.
Everything starts from a Docker image.
When you tell Docker to create a container from an image using
docker run, it will perform its magic (create the file system, initialize the dependencies, and more) and then the container will be created.
Images are built from a Dockerfile using the
docker build command, and they can be stored locally, or published in a Docker registry like Docker Hub, where you can store public and private images.
If you visit https://hub.docker.com/ you will see a lot of images you can freely use without having to create your own images.
Often times those images are official and made by the development teams behind a specific technology.
For example this is the official Node.js Docker Image: https://registry.hub.docker.com/_/node.
We’ll talk more about how to use images and containers soon.
More docker tutorials:
- Introduction to Docker
- Introduction to Docker Images
- Introduction to Docker Containers
- Installing Docker on macOS
- First steps with Docker after the installation
- Using Docker Desktop to manage a Container
- Create a simple Node.js Hello World Docker Container from scratch
- What to do if a Docker container immediately exits
- Working with Docker Containers from the command line
- Working with Docker Images from the command line
- Sharing Docker Images on Docker Hub
- How to access files outside a Docker container
- How to commit changes to a Docker image
- Updating a deployed container based on a Docker image