A semantic network is a graphical representation of knowledge that illustrates how concepts are related to one another. In this structure, nodes represent concepts or entities, while edges (lines) indicate the relationships between them. For example, a semantic network might show that dog is a type of animal, and animal is a living organism. These networks are used in various fields, including artificial intelligence and linguistics, to help machines understand and process human language. By mapping out relationships, semantic networks enable better information retrieval and reasoning, making them valuable tools for applications like natural language processing and knowledge representation.