The two terms are mutually exclusive. Firm fixed-price refers to the pricing arrangement, i.e., "item A" will cost "X dollars." IDIQ contracts (as well as requirements contracts and definite-quantity contracts) are all considered "indefinite-delivery" contracts, which provide for variable ordering/delivery schedules and/or quantities. In other words, FFP addresses the price while IDIQ addresses variability in quantities and ordering/delivery schedules. IDIQ contracts often contain FFP line items.