The original name commonly used for Facebook's News Feed ranking algorithm was EdgeRank. The name described an early system for deciding which stories, posts, photos, and other updates should appear prominently in a user's feed.
EdgeRank is usually explained through three broad factors: affinity, weight, and time decay. Affinity represented the relationship between a user and the person or page posting; weight reflected the type of interaction or content; and time decay reduced the importance of older activity.
Facebook's ranking system later became much more complex, using many signals and machine-learning models. The company generally stopped presenting EdgeRank as the official name of its current system, so the term now mainly refers to the earlier model or to Facebook feed ranking in historical discussions. It is not the same as Google's PageRank or Google's RankBrain.