ActivityPub is a protocol which is used for building decentralized social networking applications.
It provides both a server-to-server and client-to-server protocol for desktop and mobile applications to connect with to your server.
ActivityPub implementations can implement just one of these things or both of them. However, once you've implemented one, it isn't too many steps to implement the other, and there are a lot of benefits to both making your website part of the decentralized social web, and being able to use clients and client libraries that work across a wide variety of social websites.
Mastodon, the incredibly popular free software microblogging platform with over one million registered users, uses ActivityPub to unite between servers, and many more applications all ready either partially or fully support ActivityPub.
The concept of opensource decentralized platform
For example, Mastodon is an open source social network similar to Twitter or Tumblr where the user can make profiles, post messages, images or videos and also follow other users.
Messages follow a 500 character limit and are displayed in a chronological order. Unlike other platforms, mastodon is decentralized, meaning, that there is no one server, company or a person running it. While other social media platforms are owned and operated by a single corporation who has full control over everything and anyone can create and run their own server of the mastodon.
How does this work?:
When someone creates their own version of the mastodon, this is called an “instance”. Since Mastodon is open source and anyone can create their own instance of the mastodon with their own set of rules. Because of this, all instances are owned, operated and moderated by the community that creates them and not some large corporation which tracks your data to sell to advertisers.
In most cases, mastodon instances are crowdfunded not financed. But how do these instances communicate with one another? While users within an instance can, of course, follow each other they can also decide to follow users within other instances. So while each instance of the mastodon is privately operated, their users can still communicate with members of their server seamlessly. Communities who want to remain private don’t have to communicate with other servers. This is in the hands of its users.
Mastodon also offers effective anti-abuse tools to help moderate instances as users see fit. Ultimately, Mastodon is a social network which puts the user first. Unlike traditional social media, mastodon can’t go bankrupt, it can be sold, and can’t be completely blocked by governments.
Users are free to join whichever community they want and communicate with whomever they want. With over million registered users across multiple different languages, mastodon is growing fast.
Advantages of Decentralised Social Network:
Do not bind users to a particular online social network.
Give users more control over data ownership and privacy.
Each user has a personal server containing his/her data.
Each user will have a personalized face recognition engine, optimized for recognizing face images of the user in question.
Open development Spam control Distributed services Cottage opportunity
Disadvantages of Decentralised Social Network:
Difficulties in maintaining global standard & consistent data.
Higher infrastructure cost.
Loss of control Duplication of data Harder to negotiate preferential supplier agreements.