Docker’s normally used to containerise background applications and CLI programs. You can also use it to run graphical programs though! You can either use an existing X Server, where the host machine is already running a graphical environment, or you can run a VNC server within the container.

Docker containers make your app portable across environments. Once you’ve got a container image, you can use it anywhere Docker is available. Here’s how to containerise a PHP web application using the Apache server.

The Docker build context refers to the files and directories that will be available to the Docker engine when you run docker build. Anything not included in the build context won’t be accessible to commands in your Dockerfile.