The document discusses the key characteristics of a relational database. It notes that a relational database organizes data into tables with rows and columns, and establishes relationships between tables using primary and foreign keys. This allows data to be non-repetitive and accurate. Users can query any table and combine related tables using joins to retrieve the required data. Relational databases also support data integrity, easy expansion to handle more data and changes, access control through user permissions, and flexible insertion, deletion and updating of records. However, performance may be impacted if there are many tables or complex joins, and extracting meaning from hierarchical data can be slower compared to hierarchical databases.