A graph is a mathematical concept used as a non-linear data structure within computer science. Graphs are often depicted visually, and are composed of nodes (often circles or squares), and edges (often lines between nodes).
Graphs are used to solve many real-world problems, most notably as a way to represent networks. For example, within a social network each node may be a user and may be composed of the same information and structure such as name, comment history, photos, and pages being followed.
Within the context of a Knowledge Graph, the concept of a graph describes the way in which entity types are organized and interlinked. Diffbot’s Knowledge Graph™ presents nodes (entities) of many different types that help to inform each other and provide contextual knowledge. A product entity may be referenced as part of a fact (say, a list of products) within an organizational entity. A group of article entities may change the likelihood of the truth of a fact within a person entity.