Platform & DevOps·What the platform costs
you promise a year of spend in advance and pay perhaps forty percent less, and you owe it whether or not you use it.
Reserved capacity
Also calledreserved instance, savings plan, committed use discount
Committing to a level of usage over one or three years in exchange for a substantial discount. It is close to free money for a stable baseline and a liability if the architecture changes underneath it — a migration that halves your compute leaves the commitment intact. The practical approach is to commit only to the floor you are confident of and leave the variable part on demand.