How to set up and use a Docker private registry?

Docker private registries are used to store and manage private images. You can set up using the official Docker Registry image or use enhanced registries like Harbor or Nexus. Setup steps: 1) pull the registry image; 2) run the container and map storage directory and ports; 3) configure HTTPS (recommended to use Nginx reverse proxy); 4) configure authentication (use htpasswd to generate password file). Use docker login to log in to the private registry, docker push to push images, docker pull to pull images. Private registries are suitable for storing internal enterprise images, protecting sensitive code, and accelerating image pull speeds.