These are essentially RIs but on a grander scale, with larger commitments and more opportunities to negotiate discounts.
Alongside pay-as-you-go pricing, AWS also offers Reserved Instances (RIs) which, in simple terms, offer a set amount of usage at a discounted price. For larger customers, particularly those with a history of AWS usage, Enterprise Discount Programs (EDPs) are also offered. These are essentially RIs but on a grander scale, with larger commitments and more opportunities to negotiate discounts.