This guide details how to enable sharing from your app to Facebook. When someone shares from your app, their content appears on their Timeline and may appear in their friends' News Feeds.
The Share Dialog is an easy way to let people share content without having them to log into your app or grant any permissions. It works on web, Android and iOS.
People can share the following kinds of content to Facebook:
Links - Most content is a URL which references an HTML page. To provide the most relevant information, you should mark up your page with Facebook-specific meta tags. See A Guide to Sharing for Webmasters.
Photos - Directly upload one or more user-generated photos.
Videos - Directly upload a user-generated video.
Multimedia - Directly upload a combination of photos and videos.
The message dialog used to be a way to let people privately share content to Messenger. This is no longer supported and you should use native Share methods instead to allow your users to share content to Messenger and other apps.