Embedding PHP, etc into posts / pages

I’ve went through several documentation and I haven’t seen anything regarding embedding PHP, JavaScript, etc into your pages / posts?

I created a page where I would like to use php to pull data from my database and display it in a table. I want to use PHP to accomplish this but it doesn’t seem possible within wordpress?

Can someone please provide me some guidance on a mod / plugin or hopefully “out-of-the-box” functionality that allows me to accomplish this.

Thank you,

John