MySQL is a relational database management system (RDBMS) that stores data in separate tables. It has several key benefits, including being easy to use with only basic SQL knowledge required, secure with password encryption and user privileges, and inexpensive as it is freely available. MySQL is also fast despite fewer features than competitors, scalable to large amounts of data, manages memory well to prevent leaks, supports clustering for high availability, and can be used across many operating systems through interfaces like JDBC and ODBC.