Spot vs. On-Demand Instances: What’s the Difference?

Spot instances and on-demand instances are two types of AWS EC2 instances that differ primarily in cost and availability. Spot instances offer a cost-effective option by allowing users to access spare compute capacity at a discounted rate, although they can be interrupted if the resources are needed elsewhere, making them suitable for stateless workloads or those with checkpointing capabilities. In contrast, on-demand instances provide guaranteed availability without interruptions, ideal for time-sensitive or interactive tasks such as using Jupyter notebooks, albeit at a higher cost. The decision between these instance types hinges on the trade-off between cost savings and the need for uninterrupted service.