Neo4j is a popular graph database management system designed to store and manage data in a way that emphasizes relationships between data points. Unlike traditional databases that use tables, Neo4j represents data as nodes, relationships, and properties, making it easier to visualize and query complex connections. Developed by Neo4j, Inc., this database is particularly useful for applications involving social networks, recommendation systems, and fraud detection. Its query language, Cypher, allows users to easily express and retrieve data based on relationships, enhancing the efficiency of data analysis and retrieval.