What is the difference between a “lump-sum” offer and a “short-term deferred” offer?

A \”Lump-Sum\” Offer is an Offer that is calculated using net equity in assets and 12 months of future income. The offer requires 20% be put down as an initial payment when the offer is submitted, and the balance is paid over 5 months after accepted.
A short-term deferred offer is calculated using the net equity in assets and 24 months of future income. The offer is paid in monthly for no more than 24 months, starting when the offer is filed and continues until the offer is accepted or rejected. If accepted, the taxpayer continues to pay until it is complete.