The social graph is a graph that represents social relations between entities. In short, it is a 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". Since explaining the concept of the social graph, Mark Zuckerberg, one of the founders 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 Facebook's control.