I’m having a stab at a definition here, but a social network is pattern of lines of connection between people which is held together by the participants’ interests and some rules governing what it means to belong to the network.
Simply having a connection with someone though a social network is commonplace. Many people can say, for example, that they have some connection with the Royal Family or a well known celebrity; this in itself is not surprising. Having a connection to a network and properly belonging to it are not the same thing; Living in a country and belonging to it are not the same thing.
A defined social network (as opposed to casual network of random connections) has elements of enclosure that makes for what some might call a “circle”. The rules of membership may not be formally written down or acknowledged but dig deep and they will be found; Social networks can therefore be open or closed.
Closed social networks can be open in the sense that anyone can participate, but the level to which people are accepted as members may be questioned. There will be thresholds of acceptance. So, some can be present but not fully accepted.
As the identity of the network becomes more established, a core group may begin to assert ownership over the network and it will often be led by a particular individual. Vanity of the membership will not allow the group to close itself off from the world but may instead attempt to seek fame and attention – characterised by status and exclusivity.
As popularity grows, some firm rules of membership will be formed in order to protect the group from outside influences that may seek to dilute the identity of the group or perhaps challenge the power of the core group or leader. The boundaries of membership become walls in order to protect the membership.
In time, the social network becomes a nation at war with its neighbours.