The type of database that relies on a fixed schema and structured data is known as a relational database. Relational databases organize data into tables with predefined relationships between them, making it easy to execute queries using Structured Query Language (SQL). Each table has a specific structure, often defined by columns and data types, ensuring data consistency and integrity. This model is suitable for applications requiring complex queries and transactional processing. While relational databases are widely used, modern applications may also integrate NoSQL databases for more flexible data handling.