Does HTML code generally go inside of a PHP file instead of in an HTML file?

Question

I'm working on a project for a class and I'm wondering why the HTML code is placed in the PHP file. I know that with PHP, the website updates as any changes are made.

Answer 1

because part of the rational behind the use of PHP is to dynamically generate some HTML based on conditions and different checks. A PHP page with no HTML would be a blank page.