Docker Architecture

Docker's architecture follows a client-server model, consisting of three main components: the Docker Client, the Docker Daemon (or server), and the Docker Registry. The Docker Client is the primary user interface for Docker. It's the command-line tool (the `docker` command) that users interact with to issue commands. When you type a command like `docker run` or `docker build`, the client sends these commands to the Docker Daemon. The Docker Daemon (`dockerd`) is a persistent background process that manages Docker objects such as images, containers, networks, and volumes. It listens for API requests from the Docker Client and carries out the instructions. The daemon is the brain of the operation, responsible for building images, running containers, and handling all the low-level tasks. The client and daemon can run on the same system, or you can connect a Docker client to a remote Docker daemon. The third component, a Docker Registry, is a storage system for Docker images. Docker Hub is the default public registry where anyone can store and download images. When you execute `docker pull nginx`, the daemon contacts the Docker Hub registry to download the specified Nginx image. You can also host your own private registry to store proprietary images. This architecture decouples the user interface from the core logic, enabling powerful automation and remote management capabilities.