Welcome back.


In this part of the course,


I want to quickly talk about container registries.


I want to keep this theory really brief


because you're going to get the chance


to use a registry directly after this in the course,


so let's jump in and get started.


Now, container registries are like GITHUB


but for docker images.


Docker Hub is an example of a registry.


This is a public registry,


but you can run private registries


either in the cloud or on-premises.


Registries are split into repositories just like GITHUB,


so you'd create a repository for your different applications


and different container images.


Now you can run docker pull from a repository


or use docker push to a repository


and this has the effect


of pulling images from the repository


to your local docker host or pushing images


from your docker host to a repository of your choice.


Now for Docker Hub, the way everything is named is


that you have a username, a repository name, and a tag.


So for example, I might have acantril,


which is my username, forward slash containerofcats,


which is my repository name, and then latest,


which is the tag


and a repository can have many different tags


and this is a way that you can specify different versions


of a docker image and of course, latest can always point


at the latest version of a particular docker image.


Now, this is a topic which is going to be much clearer


if you learn by doing,


so coming up next,


you're going to get the chance to interact


with a docker registry, Docker Hub in this example,


and you'll get the experience


of pulling and pushing container images,


including logging into the registry


as well as tagging images,


so it's going to be much easier


for you to get this experience by doing it practically


and that's what we're going to do next.


So when you're ready, go ahead


and move on to the next part of the course.