Annotation protocol (creating a new annotation)

I'm trying to work through the protocol and I can see I'm going to have questions. I'll start with the following, and the answer will probably lead to more questions.

on server   xyz.org     there is resource R:  http:/www.xyz.org/resources/resourceR

On MY server:   http://www.ray.org/
I create a review of resource R:     http://www.ray.org/reviews/reviewOfResourceR

I create an annotation:

<http://www.ray.org/annotations/annotationForTheReviewOfResourceR>   a  oa:Annotation ;
                oa:hasBody                        <http://www.ray.org/reviews/reviewOfResourceR>  ;
                oa:hasTarget                      < http:/www.xyz.org/resources/resourceR> .


http://w3c.github.io/web-annotation/protocol/wd/   says
"3.2.1 Create a New Annotation
New Annotations are created by posting the JSON-LD serialization to an Annotation Container."
Annotation container where?  On  which server,  xyz or ray?   I assume "ray" because that's my server so I know where the annotation container is, while I have no idea where the container is on xyz.

My question is, how is server xyz made aware of the existence of this annotation?   Either I'm missing something, or the document hasn't gotten that far yet.  If it's the latter, fine, I just want to be sure I'm not missing something.

Thanks.

Ray