Docker Hub is a service provided by Docker for finding and sharing container images. It allows us to push new images and pull existing images from the Hub. DockerHub is like GitHub we can user push/pull commands to manage Docker images. GitHub allows us to store and version controls our source code, while DockerHub allows us to store and version control Docker Images. 

DockerHub is the default registry used by the Docker engine. DockerHub hosts public and private repositories, it also provides automated builds, organization accounts, and integration with source control solutions like Github and Bitbucket.