Social Graph

Social graph is the data structure that encodes social relations — friendships, followings, affiliations, interactions — as a computable network. Unlike a simple contact list, the social graph captures not just who is connected to whom but the topology of those connections: centrality, clustering, community structure, and information pathways. The social graph is the foundational infrastructure of modern social media platforms, enabling algorithmic curation, targeted advertising, and the prediction of behavior from network position.

The concept became operationally significant with Facebook, which constructed the first global social graph at billion-user scale. But the idea extends beyond any single platform. The social graph is an instance of social network analysis applied to digital infrastructure, and it raises fundamental questions about privacy, power, and the commodification of human relationships. When your connections become data, your social world becomes an input to systems you do not control.

The social graph also enables a distinctive form of inference: if two users share many mutual connections, the system can infer shared preferences, vulnerabilities, and behaviors even for users who have not explicitly disclosed them. This is the mechanism behind 'people you may know' recommendations and the predictive power of platform advertising. The social graph is not merely a map of social reality; it is an engine for shaping it.