If the business cancels
You are always refunded in full for anything you paid online. No exceptions.
If you cancel
Each business sets a refund policy: cancel before their refund window and anything paid online comes back in full; cancel inside the window and a percentage may apply. The exact policy is shown before you confirm the booking and on the booking page.
Non-refundable fees
Some businesses charge a booking or holding fee that is marked non-refundable. When that is the case it is labeled on your order summary before you pay, and refunds are calculated on the rest of the payment.
Where is my money?
Refunds go back to the card you paid with. Banks typically post them within 5 to 10 business days.