Which characteristic defines a relational database?

A relational database is distinctly characterized by its use of linked tables to organize data. This structure allows for the establishment of relationships between different datasets, making it possible to efficiently manage and query complex data. Each table represents a specific entity and contains rows and columns, where rows correspond to records and columns to attributes of those records. The key feature of a relational database is its ability to implement relationships through foreign keys and primary keys, enabling meaningful connections and data integrity between related tables. This design supports advanced querying capabilities and enhances data organization and retrieval.

In contrast, the other options describe characteristics that do not apply to relational databases. Storing data in flat files lacks the organization and relational structure offered by tables, while the idea of using only single tables contradicts the core concept of having multiple interrelated tables in a relational model. Limiting data types does not align with the relational database's flexibility to support a variety of data types, allowing for diverse data representation.