To better understand this function you should execute this code first :
<?php
// First of all choose your path , For e.g. C:/session
session_save_path('Your Path here !');
session_start();
// Define a Session Variable
$_SESSION['Key'] = 'value' ;
Var_dump(session_status() == PHP_SESSION_ACTIVE);
// Output : bool(True) , it means you have an open session !
?>
Then you should execute this code :
<?php
// Choose the path that you used it in first part
session_save_path('Your path here');
session_start();
// If you want to close session and keep your original data in your path , you should use session_abort()
session_abort();
var_dump(session_status()== PHP_SESSION_ACTIVE);
// Output : bool(False) , it means your session closed .
?>