What is the Fediverse?

The Fediverse is a network of independent social platforms that can communicate with each other.

The word Fediverse comes from:

  • federation + universe

It is like a universe of connected servers.


Simple explanation

On normal social media, one company usually controls the whole platform.

Example:

  • One company
  • One website
  • One app
  • One set of rules
  • One central network

In the Fediverse, many different servers can connect together.

Example:

  • server A
  • server B
  • server C
  • server D

Users can be on different servers and still follow, reply, like, boost, and interact with each other.


What is federation?

Federation means separate servers communicate with each other.

Example:

They are on different servers, but their servers exchange posts and interactions.


What is an instance?

An instance is a Fediverse server.

Examples:

  • mastodon.social
  • example.social
  • social.example
  • community.example

Each instance can have:

  • its own users
  • its own rules
  • its own admins
  • its own moderation style
  • its own community culture
  • its own custom emojis

Why instances matter

Choosing an instance is like choosing a community.

Different instances can focus on different topics:

  • technology
  • art
  • music
  • gaming
  • local communities
  • photography
  • writing
  • academia
  • general social posting

An instance can decide:

  • who can join
  • what rules apply
  • which servers to block
  • which servers to allow
  • what kind of community it wants to be

What is Mastodon?

Mastodon is one of the most popular Fediverse platforms.

It is similar to a microblogging platform.

Users can:

  • write posts
  • follow people
  • boost posts
  • favourite posts
  • reply to posts
  • use hashtags
  • follow people on other servers

Mastodon is part of the Fediverse because it uses ActivityPub.


What is ActivityPub?

ActivityPub is a protocol that lets different Fediverse servers communicate.

A protocol is a set of rules for communication.

ActivityPub helps servers exchange things like:

  • posts
  • follows
  • replies
  • boosts
  • likes
  • profile updates

Fediverse identity

A Fediverse account usually looks like an email address:

or:

Meaning:

  • user = username
  • example.social = instance/server

Example:


Local timeline

The local timeline shows posts from people on the same instance.

Example:

  • All public posts from users on example.social

This can make an instance feel like a small community.


Federated timeline

The federated timeline shows posts known to the instance from other servers.

It may include posts from:

  • people local users follow
  • servers the instance has interacted with
  • remote accounts known to the server

It is not always the entire Fediverse.


Home timeline

The home timeline shows posts from accounts you follow.

This is usually the most personal timeline.


Boost

A boost is similar to a repost.

When you boost a post, you share it with your followers.


Favourite

A favourite is similar to a like.

It tells the author you appreciated the post.

Depending on the platform, favourites may or may not spread the post much.


Hashtags

Hashtags help people discover posts.

Examples:

  • #Linux
  • #Fediverse
  • #Mastodon
  • #Photography
  • #Cats

Hashtags are important on the Fediverse because there is usually less algorithmic recommendation than on corporate social media.


No central algorithm

Many Fediverse platforms do not use a strong central recommendation algorithm.

This means discovery often happens through:

  • hashtags
  • boosts
  • following people
  • local timelines
  • community interaction
  • lists
  • directories

Moderation

Each instance has its own moderation.

Admins can:

  • set rules
  • remove content
  • suspend accounts
  • limit other servers
  • block other servers
  • handle reports

This means the Fediverse is not one single moderation system.

Different communities may have different standards.


Defederation

Defederation means one server blocks or disconnects from another server.

This may happen because of:

  • spam
  • abuse
  • harassment
  • bad moderation
  • illegal content
  • community safety concerns

Defederation is one way instances protect their communities.


Benefits of the Fediverse

  • many independent communities
  • less central control
  • more user choice
  • open protocols
  • different apps can communicate
  • communities can set their own rules
  • users can move to different servers

Challenges of the Fediverse

  • can be confusing for beginners
  • instance choice matters
  • moderation differs by server
  • search and discovery can feel different
  • some servers may block each other
  • moving accounts is not always perfect
  • small servers need maintenance

Simple mental model

Think of the Fediverse like email.

You can have:

Different providers, but they can still send messages to each other.

The Fediverse is similar:

Different servers, but they can still interact.