What is the best practice for navigating between directories in PHP?

When navigating between directories in PHP, it is best practice to use the `__DIR__` magic constant to get the current directory path and then use `dirname()` function to navigate to the parent directory. This ensures that your code is platform-independent and will work correctly regardless of the server's operating system.

// Get the current directory path
$currentDirectory = __DIR__;

// Navigate to the parent directory
$parentDirectory = dirname($currentDirectory);

// Now you can use $parentDirectory to access files or directories in the parent directory