What characterizes a relational database?

A relational database is characterized by its use of tables that are connected or linked through keys. These keys can be primary keys or foreign keys, which allow for the establishment of relationships between different tables. This structure enables data to be organized and accessed in a way that maintains the integrity and consistency of the information across the database. By utilizing these relationships, relational databases can efficiently manage complex data and perform operations like joins to retrieve related records from multiple tables.

Using unrelated data entries or single tables without relationships does not embody the principles of a relational database, as these characteristics would limit the database's functionality and ability to maintain associations between data. While minimizing data redundancy is a goal of relational databases through normalization, it is often not possible to prevent it entirely. Thus, the defining feature of a relational database is indeed the incorporation of tables linked through keys, allowing for structured data management and enhanced querying capabilities.