dependent parts (binaries, libraries, and code) into a
standardized package for software development.
The Docker architecture consists of three primary parts:
the client, the Docker host, and the docker registry (see
Figure 13-25).
Figure 13-25 Docker Architecture
The Docker client is a command-line utility (run with the
docker command) that talks to the REST API of the
Docker daemon so that the administrator can issue
commands for the operations and management of
Docker containers. The client can communicate to a local
or remote Docker instance.
The Docker host is where the Docker daemon resides.
The Docker daemon (dockerd) is a service that runs on
the host operating system and interfaces with the
operating system kernel to allow containers to function.
The client communicates with the Docker daemon
through the REST API. The Docker host houses running
containers and also interfaces with the registry to pull
container images housed there. When containers are
launched, the daemon looks in its local images, and if the
appropriate image is there, it launches the container; if