So let's clear this difference from this post.

A Docker Registry and a Docker Repository are two related but distinct concepts in the containerization.

A Docker Registry is a centralized location where Docker images are stored and managed. For example, It's like a library where you can find and retrieve specific books that you need. Docker Hub, Azure Container Registry and Google Container Registry are popular examples of Docker registries.

On the other hand, a Docker Repository is a collection of Docker images that are stored in a registry. Think of it like a bookshelf within the library where you can find multiple books that are related to a specific topic or project. For example, a repository might contain multiple images for different versions of an application or for different environments like development, staging, and production.(latest, alpine etc....)

In summary, 

a Docker Registry is the overall storage facility, while a Docker Repository is a specific collection of Docker images within that facility.