What is the difference between referencing an array in PHP and copying its values?

Referencing an array in PHP means creating a new variable that points to the original array. Any changes made to the referenced array will also affect the original array. On the other hand, copying an array means creating a new array with the same values as the original array, but changes made to the copied array will not affect the original array. To reference an array in PHP, you can simply assign the original array to a new variable. To copy an array, you can use the `array_merge()` function or the `array_slice()` function to create a new array with the same values.

// Referencing an array
$originalArray = [1, 2, 3];
$referencedArray = &$originalArray;

// Copying an array
$originalArray = [1, 2, 3];
$copiedArray = array_merge([], $originalArray); // Using array_merge()
// OR
$copiedArray = array_slice($originalArray, 0); // Using array_slice()