The main difference between these three kinds of requests lies in the purposes and level of detail. A Request for Proposal (RFP) is a comprehensive document that requests detailed proposals for a particular project. A Request for Information (RFI) is a preliminary inquiry seeking general information with fewer details than in the case of an RFP. A Request for Quotation (RFQ) is a request from organizations to service providers about the price of a specific product or service.