Share means you are sharing this photo, video, etc. with everyone you are friends with or with a custom group. Public means just that. Anyone in the world who is searching for something like that has access to that through your share, What power! Jorge · 1 year ago.or instance, if I find a YouTube video I like and want to put on my Facebook, if I put it on my profile page do I have to press share so my friends can see it also, or once its on my Facebook profile page my friends will see it and I don't have to click on share, help...