MariaDB and MySQL are both open-source relational database management systems (RDBMS) that are commonly used in web development and database management. Here are some key differences between the two:1. Compatibility: MariaDB is a drop-in replacement for MySQL, meaning it is fully compatible with MySQL and can be used interchangeably in most cases. This is because MariaDB was originally a fork of MySQL, with the goal of maintaining compatibility while adding new features and improvements.2. Licensing: MariaDB is released under the GNU General Public License (GPL), while MySQL is released under the GPL and the Oracle Binary Code License (BCL). This means that MariaDB is more open-source and free software than MySQL, which has some proprietary components under the BCL.3. Features: MariaDB has added several new features over the years, such as spatial data support, JSON data support, and improved performance for certain types of queries. MySQL, on the other hand, has focused more on stability and compatibility with older versions of the software.