Can tags be changed after creation?

No, tags in Docker cannot be changed after they are created. However, you can create a new tag for an existing image. This involves tagging the image with a new name or version. For example, if you have an image tagged as myimage:1.0, you can create a new tag like this:

docker tag myimage:1.0 myimage:1.1

This command creates a new tag 1.1 for the same image. The original tag 1.0 remains unchanged. If you want to "change" a tag, you would typically remove the old tag and create a new one.