Any payments processed through our integrated payment processor, Stripe, are Online Payments. (Article) (Article)
Anything else (cash, check, etc) are Offline Payments (Article)
Offline payments act as a record of payment, but no actual funds are transferred.
The same thing goes for Offline Refunds. When issuing an Offline Refund, no funds will be transferred to the client. The client didn't pay through Stripe, they must have paid through another platform, which means Stripe has nothing to refund