Reserved Instances: Capacity reservations - Amazon EC2 Reserved Instances and Other AWS Reservation Models

Reserved Instances: Capacity reservations

AWS also offers discounted hourly rates in exchange for an upfront fee and term contract. Services such as Amazon EC2 and Amazon RDS use this approach to sell reserved capacity for hourly use of Reserved Instances. For more information, see Reserved Instances in the Amazon EC2 User Guide for Linux Instances and Working with Reserved DB Instances in the Amazon Relational Database Service User Guide.

When you reserve capacity with Reserved Instances, your hourly usage is calculated at a discounted rate for instances of the same usage type in the same Availability Zone (AZ). When you launch additional instances of the same instance type in the same Availability Zone and exceed the number of instances in your reservation, AWS averages the rates of the Reserved Instances and the On-Demand Instances to give you a blended rate.