For example, there is a site site/89798749, how can I make such a link (after the word site)?

Question

PHP

another more understandable example. there is VK and there is a link to the profile https://vk.com/here id.

Answer 1

Write a router that will parse the url and return the necessary pages depending on the content of the link.

Answer 2

google: single entry point, cnc, mod_rewrite, routing.

Answer 3

https://stackoverflow.com/questions/19567532/tryin...
In htaccess you need to write:
RewriteEngine on
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*?)/? $ index.php?id=$1 [L]
Now id should be available via $_GET['id']