I\'m not quite sure what the purpose of session_names is.. Can someone please explain in what circumstances defining a name would be beneficial?
You have two sites on the same domain. (say, a blog and a forum)
They both run different pieces of software.
If they ran on the same session and used the same variables in $_SESSION, (say, user_id), they would conflict.
$_SESSION
user_id
session_name lets you give each application a different session.
session_name