What is a container?

A container is a packaging solution that will contain all the software dependencies that your application needs to run correctly. Different container platforms are available, but we will be using Docker in this book. We will be using Docker to build and run our containers for our example project.

Docker is an open source containerization solution that will enable us to package our PHP solution and run it on different development machines and deployment environments, including our continuous integration (CI) solution, which will be discussed more in Chapter 9, Continuous Integration.

Now that we have defined what containers are and the containerization solution we will be using for our project, let’s start setting up our development containers.