Docker Swarm mode (for Docker Engines of version 1.12 or newer) imports the SwarmKit libraries in order to make distributed container orchestration over multiple hosts possible and easy to operate.
The main difference between SwarmKit and Swarm Mode is that Swarm Mode is integrated into Docker itself, starting from version 1.12. This means that Swarm Mode commands such as
task are available inside the Docker client, and that through the docker command it's possible to initiate and manage Swarms, as well as deploy services and tasks:
docker swarm init: This is to initialize a Swarm cluster
docker node ls: This is used to list the available nodes
docker service tasks: This is used to list the tasks associated to ...