# Database Theory Historically, like how film audiences might not appreciate modern special effects until comparing them with past examples, the true power of relational databases can be fully recognized only in the context of the systems that came before them. Relational databases allow any table to relate to any other table through means of common fields. It is a highly flexible system, and most modern databases are relational. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://mariadb.com/docs/general-resources/database-theory.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.