What is Docker?

You’re probably wondering why we waited to talk about Docker until now, when we have already installed it and have been using the commands in order to interact with containers. The reason I chose to jump right into using it first and explaining later is that many IT folks who would have started reading something about a toolset called Docker that is open source, works on Linux, and so on—would instantly glaze over and skip this section anyway. I know I would have. Since you can now clearly see that Docker is a control mechanism that we will need to get familiar with if we plan to work with containers, hopefully your interest is now peaked rather than being dissolved. So let’s have just a few words on what Docker actually is.

Docker is an open source project—a tool set, really—that was originally designed to assist with the running of containers on Linux operating systems. Wait a minute, what? The words “Linux” and “open...