I am wondering how exactly does docker fit into CI /CD . I understand that with help of containers, you may focus on code , rather than dependencies/environment. But once you check-in your code, you will expect tools like TeamCity, Jenkins or Bamboo to take care of integration build , integration test/unit tests and deployment to target servers ( after approvals) where you will expect same Docker container image to run the built code. However, in all above, Docker is nowhere in the CI/CD cycle , though it comes into play when execution happens at server. So, why do I see articles listing it as one of the things for DevOps. I could be wrong , as I am not a DevOps guru, please enlighten !