Components of Docker and its Brief Summary
Docker Client: The first component of Docker is the client, which allows the users to communicate with Docker. Being a client-server architecture, Docker can connect to the host remotely and locally. As this component is the foremost way of interacting with Docker, it is part of the basic components. Whenever a user gives a command to Docker, this component sends the desired command to the host, which further fulfils the command using the Docker API.
Docker Image: Docker images are used to build containers and hold the entire metadata that elaborates the capabilities of the container. These images are read-only binary templates in YAML. Every image comes with numerous layers, and every layer depends on the layer below it. The first layer is called the base layer, which contains the base operating system and image. The layer with dependencies will come above this base layer. These layers will have all the necessary instructions in read-only, which will be the Dockerfile.
Docker Daemon: Docker Daemon is among the most essential components of Docker as it is directly responsible for fulfilling the actions related to containers. It mainly runs as a background process that manages parts like Docker networks, storage volumes, containers, and images. Whenever a container start up command is given through docker run, the client translates that command into an HTTP API call and returns it to the daemon. Afterwards, the daemon analyses the requests and communicates with the operating system. The Docker daemon will only respond to the Docker API requests to perform the tasks.
Docker Registry: Docker images require a location where they can be stored and the Docker registry is that location. Docker Hub is the default storage location of images that stores the public registry. However, registries can either be private or public. Every time a Docker pull request is made, the image is pulled from the desired Docker registry where it was the same.
Docker Container: A Docker container is the instance of an image that can be created, started, moved, or deleted through a Docker API. Containers are a lightweight and independent method of running applications. They can be connected to one or more networks and create a new image depending on the current state. Being a volatile Docker component, any application or data located within the container will be scrapped the moment the container is deleted or removed.