I observed that all the above term's value are different which I thought to be same.
echo $orderId = $observer->getEvent()->getOrderIds();
echo $qid = $order->getQuoteId();
$order_data= $order->getData();
echo $increment_id = $order_data['increment_id'];
Above code outputs orderId: 32, QuoteId: 41 and incremenId: 52. Why are these three values different and what they mean?