In what scenarios would using sessions be preferable to using IP addresses for tracking purposes in PHP?

Using sessions would be preferable to using IP addresses for tracking purposes in PHP when you want to track user activity across multiple pages or sessions. Sessions provide a way to store user-specific data on the server side, allowing for more reliable and secure tracking compared to relying solely on IP addresses which can change frequently, especially in cases of dynamic IP addresses or users accessing the website from different devices.

// Start a session
session_start();

// Store user-specific data in the session
$_SESSION['user_id'] = 12345;

// Retrieve user-specific data from the session
$user_id = $_SESSION['user_id'];

// Use the stored data for tracking purposes
echo "User ID: " . $user_id;