With screen sharing, users are able to share memories from their camera roll, browse an online shopping platform together, co-browse social media, and so on. Basically it is the same as live streaming, but your audience is limited to who you’re calling or the group of people that you’ve invited to participate.
Facebook mentioned that the new screen sharing feature on all versions of Messenger currently allows up to 16 users to join in. The company noted that it will soon add the ability to control who can share their screen in the web and desktop version of Messenger Rooms, as well as increasing the number of participants to 50. Screen sharing is now available to all users globally. In order to try out this new feature, be sure to get the latest versions of Facebook Messenger on Android, iOS, desktop, and web. (Source: Facebook Official Blog)