A SQL database functions as a structured system for data management, allowing for the storage, retrieval, and modification of data through SQL (Structured Query Language). SQL databases offer a systematic way to organize data into tables, enabling relationships between various datasets. This relational model supports complex queries, making it easier to extract meaningful insights from large volumes of data. SQL databases also ensure data integrity through constraints and transactions, promoting consistency. As foundational components of many web applications and enterprise systems, they play an essential role in managing and processing structured data effectively.