Where is everything stored in the WordPress Database?

Shows where data is stored in the WordPress Database.

We use the WordPress Standard tables except for our own table for Relationship Fields wp_podsrel and if you’ve enabled Table Storage or have Advanced Content Tables.

That being said, the best reference for where things are stored in WordPress is the following two reference articles from Delicious Brains:

Also be sure to check out our Fields Reference which lists the fields that are defined in each post type, taxonomy, user fields, etc.