Docker uses a client-server architecture, consisting of the following components:

Docker Client:

• The interface that users interact with.

• It sends commands to the Docker daemon.

Docker Daemon:

• The background service that manages Docker containers.

• It receives commands from the Docker client and carries them out.

Docker Images:

• Read-only templates that contain instructions for creating a container.

• They are built from a Dockerfile, which specifies the steps to create the image.

Docker Containers:

• Instances of a Docker image.

• They are isolated environments that run applications.

• Each container has its own file system, network, and process space.

Docker Registry:

• A centralized repository for storing Docker images.

• It allows users to share images with others.

Docker Hub:

• A public Docker registry that is widely used.

• It contains millions of images from various sources.

Docker Compose:

• A tool for defining and running multi-container Docker applications.

• It allows users to manage multiple containers as a single unit.

Docker Swarm:

• A tool for clustering and orchestrating Docker containers.

• It allows users to scale applications horizontally and manage multiple hosts.

Docker Machine:

• A tool for provisioning Docker hosts on various platforms.

• It allows users to create and manage Docker hosts on cloud platforms, virtual machines, and bare metal.

Docker uses a layered file system to optimize image storage and sharing. Each layer represents a change to the image. Layers are cached and reused, which can significantly improve image build times and reduce storage requirements.