MySQL is an open-source DBMS which is developed and distributed by Oracle Corporation.
It is supported by most of the popular operating systems, such as Windows, Linux, etc. It can be used to develop different types of applications but it is mainly used for developing web applications.
MySQL uses GPL(GNU General Public License) license so that anyone can download and install it for developing those applications which will be published or distributed freely. But if a user wants to develop any commercial application using MySQL then he/she will need to buy the commercial version of MySQL.