What are image tags? Why is it recommended to use tags when supporting multiple releases/versions of a project?

Image tags are used to distinguish between multiple versions of the same software or project. Let's say you developed a project called "FluffyUnicorn" and the current release is 1.0. You are about to release 1.1 but you still want to keep 1.0 as stable release for anyone who is interested in it. What would you do? If your answer is create another, separate new image, then you probably want to rethink the idea and just create a new image tag for the new release.

In addition, it's important to note that container registries support tags. So when pulling an image, you can specify a specific tag of that image.