Which AWS service or pricing model can provide the GREATEST cost savings?

Explanations:

Capacity Reservations ensure capacity availability for EC2 instances but do not provide cost savings. They are used for ensuring you can reserve EC2 instances in a particular region, but they do not reduce costs significantly compared to other options.

Amazon Lightsail is a simpler, lower-cost option designed for small applications and workloads, but it does not provide the same level of cost savings or flexibility as Spot Instances for fault-tolerant workloads.

Spot Instances provide significant cost savings by allowing you to use unused EC2 capacity at a lower price. They are ideal for fault-tolerant workloads that can tolerate interruptions, offering the greatest cost savings compared to the other options.

Dedicated Hosts provide physical servers dedicated to your use. While they offer cost savings in some cases, they are typically more expensive than other pricing models like Spot Instances and are not as effective for workloads that do not require dedicated hardware.