MariaDB is a database system used to store and organize WordPress data — posts, comments, users, and settings. It was created as a community-driven alternative to MySQL, built by some of the same original developers.
Because MariaDB was designed to be compatible with MySQL, WordPress works with either one without needing any special configuration. In fact, many hosting providers use MariaDB by default, even though most WordPress documentation still refers to “MySQL” out of habit.
Why MariaDB Exists
MariaDB was created after concerns arose about MySQL’s direction following a corporate acquisition. Developers wanted to keep the software fully open-source, and MariaDB has since grown into a widely trusted, independent option.
Do You Need to Choose Between Them?
Not really. Most hosting providers pick one for you, and the difference is largely invisible to a typical WordPress site owner. Both work reliably for the vast majority of WordPress sites without any noticeable difference in day-to-day use.