How does a Request for Proposal (RFP) differ from an Offer?

Requests for Proposal are almost the same as an Offer, with the same key parameters specified (territory, timeframe, rights type & exclusivity).

The only difference is that the Buyer has no idea where to start the offer from a price point of view, so they are requesting that you propose the starting price for the license fee. After you respond, the Offer/Counter-offer process is identical.