Where are the posts and the database held?

Posts are stored in a table in a MySQL database. MySQL databases do not store anything in Files that are visible on your web site. i.e. – you won’t find database data in any folder.

Ok, so how can I access them directly?
There has to be some unhide alternative.

I’d like to make my own database tables, and I would also like to know how to link something in a post to the proper file path. That’s kind of hard if you don’t know where in the file path you are when you’re editing a post.

Posts have URLs you can link to, but they don’t point to any real file. Instead, they are translated by WordPress into a request to access the post from the table in the database and display it in the format defined by the WordPress template files for the template you specified (or defaulted for you).

Technically, it is possible for the database to reside on the other side of the world on a completely different domain name, web server, etc. I have, in fact, done that when moving WordPress from one web hosting file to another. Move the files first, then the database later.

Since you asked specifically about linking to posts, here is the official doc.: https://codex.www.ads-software.com/Linking_Posts_Pages_and_Categories
Note how, without Permalinks setup, you specify the Post Number: <a href="index.php?p=123">Post Title</a> as ?p=123 which, in essence says, call program index.php and pass it a parameter p with a value of 123 which index.php will translate into a retrieval from the relevant database table.

Ok I get it now,
thank you.