idk what this php code does can someone tell me? [closed]

<?php

$seed = 'COPY_RAFFLE_SEED_HERE'; // Randomly generated seed [Seed:]
$raffle_id = 'COPY_RAFFLE_ID_HERE'; // Raffle ID [Raffle ID:]
$entries = 10; // Number of tickets [Entries count:]

/*
*
* Must +1 return value since it starts with 0
* 28 characters offset to get 4 characters from both hashes
*
*/

$randomNumber = (hexdec(substr(md5($seed) . md5($raffle_id), 28, 8)) % $entries)+1; // Must use +1 as it starts with 0
echo "Ticket with number #$randomNumber won";

apparently this is the code used for the giveaways, and i wanted to see how it works