What is the function of the 'docker pull' command?

The 'docker pull' command is specifically designed to download images from a Docker registry, which is essentially a repository that stores Docker images. This command connects to the registry, retrieves the specified image, and stores it in the local Docker image cache. This is fundamental in the Docker workflow, as images serve as the blueprints for containers.

By using 'docker pull', users can ensure they have the latest version of an image or obtain an image that is needed to create a container based on that image's specifications. When working with Docker, having the right images available locally is crucial for building and running applications.

The other options involve functionalities that the 'docker pull' command does not provide. For instance, creating a container, stopping a running container, or removing a local image are handled by other specific commands such as 'docker create', 'docker stop', and 'docker rmi', respectively. Therefore, the primary and correct function of 'docker pull' is to download an image from a Docker registry.