The Docker approach to containerization is focused on the ability to take down a part of an application, to update or repair, without unnecessarily taking down the whole app. In addition to this microservices-based approach, you can share processes amongst multiple apps in much the same way that service-oriented architecture (SOA) works.
Layers and image version control
Each Docker image file is made up of a series of layers. These layers are combined into a single image. A layer is created when the image changes. Every time a user specifies a command, such as run or copy, a new layer gets created.
Docker reuses these layers for new container builds, which makes the build process much faster. Intermediate changes are shared between images, further improving speed, size, and efficiency. Inherent to layering is version control. Every time there’s a new change, you essentially have a built-in changelog—full control over your container images.
Perhaps the best part about layering is the ability to roll back. Every image has layers. Don’t like the current iteration of an image? Roll it back to the previous version. This supports an agile development approach and helps make continuous integration and deployment (CI/CD) a reality from a tools perspective.
Getting new hardware up, running, provisioned, and available used to take days. And the level of effort and overhead was burdensome. Docker-based containers can reduce deployment to seconds. By creating a container for each process, you can quickly share those similar processes with new apps. And, since an OS doesn’t need to boot to add or move a container, deployment times are substantially shorter. On top of this, with the speed of deployment, you can easily and cost-effectively create and destroy data created by your containers without concern.
So, Docker technology is a more granular, controllable, microservices-based approach that places greater value on efficiency.