Docker Basics

An introductory guide to the fundamental concepts and components of Docker.

By Kevin McAleer,    3 Minutes


Understanding the Basics of Docker

Docker is a powerful tool that has revolutionized the way software is developed and deployed. This lesson introduces you to the fundamental concepts and components of Docker, ensuring you have a solid foundation for your Docker journey.


What is Docker?

Docker is a platform for developing, shipping, and running applications. It enables you to separate your applications from your infrastructure so you can deliver software quickly. Docker provides the ability to package and run an application in a loosely isolated environment called a container.


Key Concepts of Docker

  1. Containers: Containers are lightweight, standalone, executable packages that include everything needed to run a piece of software, including the code, runtime, libraries, and system tools.

  2. Images: A Docker image is a lightweight, standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries, and settings.

  3. Dockerfile: A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image.

  4. Docker Hub: Docker Hub is a service provided by Docker for finding and sharing container images with your team.


Installing Docker

The process of installing Docker varies based on your operating system. Check the previous lesson on ā€œInstalling Dockerā€ for detailed instructions for Windows, MacOS, and Linux.


Running Your First Container

  1. Pull an Image:
    • Use docker pull [image-name] to download an image from Docker Hub. For example, docker pull hello-world.
  2. Run a Container:
    • Use docker run [image-name] to run a container from the image. For instance, docker run hello-world will run the hello-world container.
  3. List Running Containers:
    • Use docker ps to list all running containers.

Basic Docker Commands

  • docker pull: Downloads an image from Docker Hub.
  • docker run: Runs a container from an image.
  • docker ps: Lists running containers.
  • docker stop: Stops a running container.
  • docker rm: Removes a container.
  • docker rmi: Removes an image.
  • docker build: Builds an image from a Dockerfile.

Lesson Summary

Docker is a powerful tool that simplifies the process of developing, deploying, and running applications. By using Docker, you can quickly deploy and scale applications into any environment and know your code will run.


This lesson provided a brief overview of Docker, its key concepts, and basic commands. Understanding these fundamentals is crucial for working efficiently with Docker and leveraging its full potential in software development and deployment.


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