In the real world, a social community is a group of people who share some common conditions. This broad definition includes, for example, communities of people located in a precise geographical area, people with the same political or religious belief, or people sharing a specific interest, such as reading books.

The concept of social communities is also central to social media platforms. The boundaries of a community in a virtual environment can be more blurred than in the real world as, for example, the geographical aspect is less determinant. Just like in a face-to-face situation, a community naturally appears on a social media platform when people with common interest or condition start to interact.

We can make the first distinction between different types of communities depending on whether their members explicitly understand being part of it. In explicit communities, members and non-members know exactly whether they belong to the community or not, and usually understand...