What is the function of a Spot Fleet in AWS?

A Spot Fleet is a service that enables users to manage a collection of Spot Instances, allowing them to optimize both costs and availability by leveraging multiple instance types and sizes across various Availability Zones. Spot Instances are often available at a lower cost than On-Demand Instances because they're spare EC2 capacity that AWS offers to users willing to bid for it. By using a Spot Fleet, you can specify the target number of instances you want and the price you're willing to pay, enabling AWS to launch instances that meet your criteria.

The ability to use a Spot Fleet is significant for applications or workloads that can tolerate interruptions and where lower costs are a priority. Spot Fleets can automatically request and manage the instances to ensure that your application has the necessary resources while maintaining cost efficiency. This flexibility in choosing instance types provides the opportunity to take advantage of varying prices across regions and availability zones, ultimately leading to cost optimization.