Choosing to share your content with another archive means that members of that archive can view all of your published stories (written and visual), as well as all of your social posts. Family historians of that archive will also have the ability to edit your contributions.
See "What does content visibility mean?" to learn more about this setting.
See "How do I change my content visibility settings?" to learn how to share your content.
If you have any doubts, don't hesitate to get in touch with us at firstname.lastname@example.org