I can see that you can create a Service Connection in Azure DevOps for:
I can understand the Docker Registry - This allows you to configure a connection to some private registry which only allows authenticated users to log in and push/pull. But I can't understand what is the Docker Host Service Connection. What is it good for?
Docker Host Service Connection is a legacy of a unpublished task Docker Integration.
The Docker Integration extension introduces two new service endpoints for Docker hosts and registries. The tasks default to using a local Docker host if available (this currently requires a custom VSTS agent), otherwise they require a Docker host connection to be provided.
Because this task is in an unpublished state at this time, we cannot use it. If necessary, it is recommended to use equivalent built-in docker and Docker Compose tasks.
Docker Host service connection: Defines and secures a connection to a Docker host.
Ensure you protect your connection to the Docker host. Learn more.
