Docker is a freemium development kit set of software-as-a-service and platform-as-a-service products that can develop and deliver software in packages called containers. It allows you to package up an application with all of the parts it needs so it will always run the same wherever you move it. Docker has both free and premium tier services for various users—its target audience mostly developers, IT operations, and business leaders. This tool can get more applications running on the same hardware, makes it easy to quickly create ready-to-run containerized applications, and makes managing and deploying applications hassle-free. It’s a popular platform choice for IT services.