Docker architecture has three main parts: Docker Client, Docker Daemon, and Docker Registry. When I run a command like docker run, the Docker Client sends that request to the Docker Daemon. The Docker Daemon is the main engine that builds images, creates containers, manages networks, and handles storage. If the image is not available on my system, the Docker Daemon pulls it from a Docker Registry like Docker Hub. Once the image is available, Docker creates a container from that image and starts the application inside it. So the flow is: I give a command through the Docker Client, the Docker Daemon processes it, downloads the image from the Docker Registry if needed, creates a container, and then runs the application.