Backing up your WordPress database is critical to recovering your website following a system crash. You should either have an automated system in place to back your site up or, on a regular basis, follow the steps I will show you in the video below. Keep in mind that the steps I will show you are for backing up your database only which includes your posts, pages, photos, and other items that make up the content of your site. It does not back up your WordPress system files that make up the infrastructure of your site. So, at a minimum, also use FTP or another method to back up your themes and plug-ins.
Here is how to back up your database.