An entity is a real-world object, concept, person, place, product, or organization. Entities form the core components of semantic keyword research, shifting the focus from simple keywords (“strings”) to real-world concepts (“things”). Entity extraction, often performed using tools like the Google Natural Language API, identifies and classifies these entities within text or queries, tagging their type (person, organization, event, etc.) and assigning a Salience Score (prominence). Entities serve as the nodes in a Knowledge Graph, connected by relationships called edges. Semantic keyword research is based on understanding these entity structures, their attributes, and their variables.