What is the name of the standard programmatic interface that the Docker client uses to communicate with the Docker daemon?

The standard programmatic interface that the Docker client uses to communicate with the Docker daemon is called the Docker Engine API. The Docker client, which refers to the `docker` command-line interface or any other program that interacts with Docker, sends instructions to the Docker daemon. The Docker daemon, also known as `dockerd`, is the persistent background process running on the host machine responsible for building, running, and managing Docker objects like images, containers, networks, and volumes. A programmatic interface is a set of defined rules, specifications, and methods that allow different software components to interact and exchange information. The Docker Engine API is a RESTful API, which means it follows the Representational State Transfer architectural style. This style uses standard HTTP methods such as GET, POST, and DELETE to perform operations on resources, which in Docker's context include containers, images, and networks. When a user executes a Docker command, for example, `docker run myimage`, the Docker client translates this into one or more specific HTTP requests that conform to the Docker Engine API specification. These requests are then transmitted to the Docker daemon, which processes them to execute the desired actions, such as pulling an image or starting a container. The daemon then sends back HTTP responses containing the results, status, or any error messages. This communication primarily takes place over an underlying transport mechanism, typically a Unix socket on Linux systems (e.g., `/var/run/docker.sock`) for local inter-process communication, or a TCP socket for remote communication with the daemon.