We can run multiple Docker containers on the same host. These containers can share Kernel resources. Each container runs on its own Operating System and it has its own user space and libraries. So in a way, Docker container does not share resources within its own namespace. But the resources that are not in the isolated namespace are shared between containers. These are the Kernel resources of the host machine that have just one copy. So in the back end, there is the same set of resources that Docker Containers share.