What is Docker?


Docker is an open-source platform that automates the deployment, scaling, and management of applications by using containers. Containers package an application and its dependencies into a single, portable unit, making it easier to run and maintain across different environments.


Imagine you're a company that sells exotic plants that need very specific conditions to thrive. If you were to just ship out seedlings or fully grown plants in a box, there's no guarantee that they would survive in transit, or thrive in the customer's climate. So to make sure every customer receives a plant that can fully thrive, you create sealed terrariums.

Docker containers are like those terrariums — Docker containers act as little microcosms that give your application a consistent environment to run in, regardless of the server, operating system, or architecture it's installed in.

To take the analogy further, imagine your terrariums are super high-tech and can be shipped disassembled. Your team of botanists programs instructions into the terrariums to assemble itself and create the proper climate for the plants within. In the Docker world, this exists in the form of a tool called Docker Compose, a tool that essentially contains and reads a blueprint for your entire application environment.

Docker Compose is the equivalent of that self-assembling terrarium — you can ship your application to any server or computer in the world, and Docker will self-assemble the environment and conditions it needs for the application within to run.

In other words

Docker is a tool that helps package software environments so they are easier to run and maintain.

Why is Docker important?

It's one thing to know what Docker is, but that is worthless if you don't know why you should know what Docker is in the first place. Let's break down the importance of this tech term based on two high-level categories. We'll walk through an explanation as well as provide a score, 1-10, that shows you how much you should care about Docker.

Pre-Product: 4/10

If you don't have a product yet, Docker may not be immediately relevant to your startup. However, it's still useful to be aware of Docker as a tool that can streamline your development process once you start building your product.

Live Product: 6/10

For startups with a live product, Docker becomes more important as it helps ensure consistent application performance across various environments. It simplifies deployment, scaling, and updates, ultimately saving time and resources for your development team.

Example Use Cases of Docker

So you know what Docker is, by definition. You know if you should care about it or not depending on your situation as a business/company/product. To dig in deeper, we will walk through some tools and processes so we can make sure you really have a solid grasp on Docker.


A Dockerfile is a script containing instructions to build a Docker image. It specifies the base image, application code, dependencies, and configurations required for the container. Developers can use Dockerfiles to create custom images tailored to their application's needs, ensuring a consistent environment across different stages of development.

Docker Compose

Docker Compose is a tool for defining and running multi-container Docker applications. It uses a YAML file to configure the application's services, networks, and volumes, making it easy to manage complex applications with multiple containers. Docker Compose simplifies the process of spinning up and tearing down environments, streamlining development and testing.

Docker Hub

Docker Hub is a cloud-based registry service that allows developers to share and distribute Docker images. It hosts both official images from software vendors and community-contributed images. Developers can use Docker Hub to find pre-built images for various applications, reducing the time spent on setting up environments.

Key Takeaways

  1. Docker is an open-source platform that uses containers to automate the deployment, scaling, and management of applications.
  2. If you do not yet have a product, Docker may not be immediately relevant but is still useful to be aware of for future development.
  3. If you do have a product, Docker is important for ensuring consistent application performance and simplifying deployment, scaling, and updates.
  4. Examples of Docker tools include Dockerfile, Docker Compose, and Docker Hub.

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