A semantic network is a graphical representation of knowledge that illustrates how concepts are related to one another. In this structure, nodes represent ideas or entities, while edges (lines) connect these nodes to show relationships. For example, a semantic network might connect the node for dog to animal and pet, indicating that a dog is a type of animal and can be a pet. 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 in knowledge representation.