Social graph

The social graph in the Internet context is a graph that depicts personal relations of internet users. In short, it is model or representation of a social network, where the word graph has been taken from graph theory. The social graph has been referred to as "the global mapping of everybody and how they're related".

The term was popularized at the Facebook F8 conference on May 24, 2007, when it was used to explain how the newly introduced Facebook Platform would take advantage of the relationships between individuals to offer a richer online experience. The definition has been expanded to refer to a social graph of all Internet users.

Since explaining the concept of the social graph, Mark Zuckerberg, founder of Facebook, has often touted Facebook's goal of offering the website's social graph to other websites so that a user's relationships can be put to use on websites outside of Facebook's control. This can be accomplished through the Facebook API.

One of the earliest known forms of the social graph was created in 2002 by Harvard student Philippe Bouzaglou in a paper published on the Harvard Department of Economics website. The paper replicated the Kevin Bacon Game using Harvard students and for the first time, gave an overview of an entire social graph, allowing the analysis of the characteristics of the network using graph theory. This paper was written for a seminar that was attended by Dustin Moskovitz who later became a Facebook co-founder.

Several issues have come forward regarding the existing implementation of the social graph owned by Facebook. For example, currently, a social networking service is unaware of the relationships forged between individuals on a different service. This creates an online experience that is not seamless, and instead provides for a fragmented experience due to the lack of an openly available graph between services. In addition, existing services define relationships differently.

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Wikipedia