Mastodon is a microblogging social network project that lets you publish short messages, photos and videos, interact with others and follow other accounts' publications.
It lets you use existing Mastodon networks or create your own social network by installing it on a server. This allows you to define your own rules of operation and moderation, and to regulate publications.
Each Mastodon can be connected to other Mastodons, enabling exchanges between these federated networks.
Mastodon also enables you to connect to different types of networks (Mobilizon, Peertube...) and follow the news of different publications on these networks.
Project description (en): https://joinmastodon.org/en
SITUATION DE DÉCOUVERTE
It might be a good idea to suggest that users discover existing networks such as https://framapiaf.org and then create an account on another mastodon server to follow people from Framapiaf (Mastodon managed by the Framasoft association).
In a school context, it might be a good idea for schools to have their own Mastodon server (for internal use only) and to regulate the publication and moderation of messages published on this server.