How does RewriteRule work in this case?

Question

htaccess

I decided to understand in detail how htaccess works.
Structure like this:

For example URL: project1.local/helloworld

Why is there an internal server error in this case? Can't start with an absolute path?

RewriteEngine On
RewriteRule . /index.php

Also a mistake. Why doesn't the redirect to /test/index.php work?

RewriteEngine On
RewriteBase /test
RewriteRule . index.php

Answer 1

the redirect directive to the php index is different.
as usual, it already exists. in the apache config
DirectoryIndex index.php index.html index.htm
with such a directive, without even entering the name of the file, the web server will try to execute
them. The priority of the files is their order.