Reserved Instances
A pricing model giving a large discount for committing to specific instance usage for one or three years.
Reserved Instances (RIs) are a billing discount applied to On-Demand EC2 usage when a customer commits to a consistent instance type and AWS Region for a one- or three-year term. Payment options range from No Upfront to Partial Upfront to All Upfront, with deeper discounts for larger upfront payments and longer terms. Standard RIs lock in the instance family, while Convertible RIs trade some discount for the flexibility to change instance attributes during the term. The key exam distinction is between RIs and Savings Plans: Compute Savings Plans apply discounts automatically across instance families, sizes, and even Fargate and Lambda, making them more flexible. RIs suit stable workloads with a known instance type; Savings Plans suit teams wanting coverage without specifying instance details.
PlayPrepHQ study notes are written and reviewed against primary exam sources. How we create & review content →