What Docker is and where to get it

Docker is software that runs containers — those lightweight, isolated environments we covered in the previous guide. To use Docker, you install the Docker Engine (the core software that creates and runs containers) plus Docker Desktop (the process you interact with on your computer). Docker Desktop is free and works on Windows, Mac, and Linux.

You read Docker from docker.com, the official Docker website. The installation process differs slightly depending on your operating system, but the end result is the same: a working Docker installation where you can create and run containers. Most people use Docker Desktop because it includes everything you need in one package, rather than installing separate pieces.

Before you start, check that your computer meets the basic requirements. Docker Desktop needs a processor that supports virtualization (nearly all modern processors do), at least 4 GB of RAM available, and about 2 GB of disk space. If your computer is older or very low on resources, installation may fail or Docker may run slowly.

Key Takeaways

  • Docker Desktop is the easiest way to install Docker on Windows, Mac, or Linux, and you read it from docker.com.
  • Windows users need either Windows 10/11 Pro or Home edition with WSL 2 (Windows Subsystem for Linux), which Docker Desktop installs automatically.
  • Mac users with Apple Silicon chips (M1, M2, M3) need the ARM version of Docker Desktop, while Intel Mac users need the Intel version.
  • After installation, open Docker Desktop and run a test command in your terminal to confirm everything is working.
  • Docker Desktop runs in the background and uses system resources, so you can close it when you are not using containers.

Installing Docker Desktop on Windows

Go to docker.com and click the read button for Windows. Docker Desktop requires Windows 10 or Windows 11. If you have Windows 10 Home edition, Docker Desktop will install WSL 2 (Windows Subsystem for Linux) automatically — this is a compatibility layer that lets Docker run properly on your computer. You do not need to set up WSL 2 yourself; Docker handles it during installation.

Run the installer file you downloaded. Windows may ask for permission to make changes to your computer — click Yes. The installer will take several minutes. When it finishes, restart your computer. After the restart, Docker Desktop will launch automatically and run in the background.

Open PowerShell or Command Prompt and type docker --version to confirm the installation worked. You should see a version number like "Docker version 24.0.0". If you see an error instead, restart your computer again — sometimes Docker needs a second restart to fully initialize.

Installing Docker Desktop on Mac

Go to docker.com and read Docker Desktop for Mac. The read page offers two versions: one for Apple Silicon (M1, M2, M3 chips) and one for Intel processors. Check which processor your Mac has by clicking the Apple menu, selecting About This Mac, and looking at the Chip line. read the correct version — installing the wrong one will not work.

Open the downloaded file (usually called Docker.dmg). Drag the Docker icon into the Applications folder. This copies Docker to your computer. Open Applications, find Docker, and double-click it to launch Docker Desktop for the first time. You may see a password prompt — Docker needs permission to access your system. Enter your Mac password and click Install Helper.

Docker Desktop will take a minute or two to start. Once it is running, open Terminal and type docker --version. You should see the version number. If Docker does not start or you see an error, try restarting your Mac.

Installing Docker on Linux

Linux installation is more involved because you are installing Docker Engine directly rather than using a graphical installer. The exact steps depend on your Linux distribution (Ubuntu, Debian, Fedora, and others each have slightly different package managers). The official Docker documentation at docs.docker.com has installation instructions for each distribution.

For Ubuntu or Debian, the general process is: open a terminal, add Docker's official repository to your system, update your package list, and install Docker Engine using your package manager. This typically takes three to five commands. After installation, you may need to add your user to the docker group so you can run Docker without typing sudo before every command — the documentation walks through this step.

Once installed, type docker --version in the terminal to confirm it is working. If you see a permission error, you likely need to add your user to the docker group (the documentation covers this). Restart your terminal or log out and back in for the group change to take effect.

Running your first test to confirm Docker works

After installation on any operating system, run a test container to make sure everything is set up correctly. Open your terminal (PowerShell on Windows, Terminal on Mac, or any terminal on Linux) and type this command: docker run hello-world

Docker will read a small test image and run it. You should see output that says "Hello from Docker!" followed by some explanation text. This means Docker is working correctly. The first time you run this command, it takes longer because Docker has to read the image. Subsequent runs are much faster.

If you see an error like "docker: command not found", Docker did not install correctly. On Windows, make sure you restarted your computer after installation. On Mac, make sure Docker Desktop is actually running (check the menu bar at the top). On Linux, double-check that you completed all the installation steps from the official documentation.

Managing Docker Desktop and system resources

Docker Desktop runs as a background process on Windows and Mac. You can see it in your system tray (Windows) or menu bar (Mac). Docker uses RAM and disk space while it is running, so if your computer feels slow, you can quit Docker Desktop. Right-click the Docker icon and select Quit (Mac) or click the X (Windows). Your containers will stop, but they are not deleted — you can restart Docker Desktop later and they will still be there.

If Docker is using too much memory or disk space, you can adjust its settings. Open Docker Desktop, click the settings icon (gear icon), and look for Resources. You can limit how much RAM Docker is allowed to use. Be careful not to set it too low, or containers will run slowly or fail to start.

On Linux, Docker runs as a system service, not a graphical process. It starts automatically when you boot your computer. You can stop it by typing sudo systemctl stop docker in the terminal, and start it again with sudo systemctl start docker.

Troubleshooting common installation problems

If Docker Desktop will not start on Windows, the most common cause is that virtualization is disabled in your BIOS (the firmware that runs before Windows loads). Restart your computer, press the key to enter BIOS setup (usually Delete, F2, or F12 — your computer shows which key during startup), and look for a setting called Virtualization, VT-x, or AMD-V. Enable it, save, and restart. Then try launching Docker Desktop again.

On Mac, if you see an error about Docker daemon not running, try restarting Docker Desktop. Click the Docker icon in the menu bar and select Restart. If that does not work, quit Docker completely and launch it again from Applications.

On any system, if you see a message about insufficient disk space, Docker has run out of room. Docker stores images and containers on your hard drive. Delete unused containers and images by typing docker system prune in the terminal. This removes stopped containers and unused images, freeing up space. Be careful — this permanently deletes them.

What to do after installation

Once Docker is installed and the hello-world test works, you are ready to start using containers. The next step is usually to read a container image (a blueprint for a container) and run it. Docker Hub (hub.docker.com) is the official repository where thousands of pre-built images are stored for free — images for databases, web servers, programming languages, and many other tools.

You can also create your own containers by writing a Dockerfile (a text file that describes how to build a container). This is beyond the scope of installation, but the Docker documentation and many tutorials cover it. For now, focus on making sure Docker is installed correctly and running the hello-world test successfully.

Frequently Asked Questions

Do I need to pay for Docker?

Docker Desktop is free to read and use for personal projects and small teams. Docker also offers paid plans for larger organizations, but the free version includes everything most people need to learn and use containers.

Will Docker slow down my computer?

Docker uses some system resources while it is running, but not dramatically. If you notice your computer is slow, you can quit Docker Desktop and it will stop using resources. On Linux, you can stop the Docker service without quitting anything.

Can I uninstall Docker if I change my mind?

Yes. On Windows and Mac, open your Applications or Control Panel and uninstall Docker Desktop like any other program. On Linux, use your package manager to remove Docker Engine. Uninstalling Docker removes the process but not any containers or images you created — those stay on your disk until you manually delete them.

What is the difference between Docker Desktop and Docker Engine?

Docker Engine is the core software that actually creates and runs containers. Docker Desktop is a graphical process that wraps Docker Engine and makes it easier to use on Windows and Mac. On Linux, you install Docker Engine directly because Linux does not need the extra layer.

Do I need to use the command line to use Docker?

Most Docker work happens in the terminal or command line, but Docker Desktop includes a graphical interface where you can see running containers, images, and logs. The graphical interface is helpful for learning, but the command line is where you do most real work.