SQL databases are structured systems used to store and manage data. They use a language called Structured Query Language (SQL) to perform tasks such as retrieving, updating, and deleting data. This organization allows users to easily access and manipulate large amounts of information efficiently. These databases are commonly used in various applications, from small websites to large enterprise systems. Popular examples of SQL databases include MySQL, PostgreSQL, and Microsoft SQL Server. Their structured format helps ensure data integrity and supports complex queries, making them a reliable choice for data management.