Docker Swarm is a native orchestration tool from Docker itself. It manages a pool of Docker hosts and turns them into a single virtual Docker host. Docker Swarm provides a standard Docker API to manage containers on the cluster. It's easy for users to move to Docker Swarm if they are already using Docker to manage their containers.
Docker Swarm follows a swap, plug, and play principle. This provides pluggable scheduling algorithms, a broad registry, and discovery backend support in the cluster. Users can use various scheduling algorithms and discovery backends as per their needs. The following diagram represents the Docker Swarm architecture: