What are Azure Reservations?
Azure Reservations help you save money by pre-paying for one-year or three-years of virtual machine, SQL Database compute capacity, Azure Cosmos DB throughput, or other Azure resources. Pre-paying allows you to get a discount on the resources you use. Reservations can significantly reduce your virtual machine, SQL database compute, Azure Cosmos DB, and other resource costs up to 72% compared to pay-as-you-go prices. Reservations provide a billing discount and don’t affect the runtime state of your resources