How can a string in PHP be split into different parts based on specific criteria?

To split a string in PHP into different parts based on specific criteria, you can use the `explode()` function. This function takes a delimiter as the first argument and the string to be split as the second argument, and returns an array of substrings. You can then access each part of the split string by iterating through the array.

$string = "apple,banana,orange";
$delimiter = ",";
$parts = explode($delimiter, $string);

foreach ($parts as $part) {
    echo $part . "<br>";
}