When I enter localhost/abc.php in the URL, it says "not found". Why?

Question

When I enter localhost/abc.php in the URL, it says "not found". Why? Those of phpstudy are all downloaded from the website and followed step by step as taught by the teacher. Why is it 404 when I open it? Is my server root directory incorrect? Ask God for answers

Answer 1

Simply speaking, localhost/abc.php accesses the directory www/abc.php file