A recurring product is a subscription purchase that repeats on a set frequency (e.g. monthly). During the first recurring checkout, you would be required to authorise a mandate (by making a RM1 transaction) or authorise a card tokenisation (by OTP/2FA). All recurring payments will be collected from you automatically based on your billing cycle.
A one-off product is essentially a one-off purchase. There will be only one payment made for this product and this payment will be paid in full during checkout.