The meaning of a deferred payment is to take possession of the item or other merchandise and then make a payment or payments at a later date that could be a month later or a few months later.
The deferred payments can also be done in court for owing other debt etc.
When you have a deferred payment plan you can make the payments at a later date which is determined by the place that you're making payments too.
For example if I bought a car and then I had a deferred payment plan it could mean that I don't start making payments on the car loan until a month later or it could be 6 months later depending on the loan agreement.
I can still take possession of the car under the deferred payment plan but I then make the payments later.