What happens if session name is same on two different websites?

Question

I have a two diff. project on my XAMPP say it is Project1 and Project2.
When i login with Project1, i check authentic

Answer 1

So suppose the server is sharing then what should I do to prevent it?

To answer your follow up question. You can simply name your session on a specific website using session_name() before your session_start().

session_name('PROJECT1');
session_start();

this one-liner should do it.