Glossary

Spot Instances

What are spot instances?


As with any cloud service provider, AWS will have spare capacity available to support surges in customer demand. To offset the loss, AWS offers this excess EC2 capacity – in other words, spot instances – at a heavily discounted rate.


To benefit from these spot instances, users must bid on this unused EC2 capacity in their desired region. The capacity is then allocated to the highest bidder. While it can be a great way to reduce costs by as much as 90%, it is only suitable for workloads that can tolerate interruptions and don’t require continuous availability. This is because AWS will terminate the instance after a two-minute notification in the event that it needs to reclaim the resources, or because the spot price exceeds the bid price. In other words, when other customers are willing to pay more.

What are spot instances?


As with any cloud service provider, AWS will have spare capacity available to support surges in customer demand. To offset the loss, AWS offers this excess EC2 capacity – in other words, spot instances – at a heavily discounted rate.


To benefit from these spot instances, users must bid on this unused EC2 capacity in their desired region. The capacity is then allocated to the highest bidder. While it can be a great way to reduce costs by as much as 90%, it is only suitable for workloads that can tolerate interruptions and don’t require continuous availability. This is because AWS will terminate the instance after a two-minute notification in the event that it needs to reclaim the resources, or because the spot price exceeds the bid price. In other words, when other customers are willing to pay more.

Related Definitions

Cloud Cost Optimization

What is Cloud Cost Optimization?


Cloud cost optimization refers to the process of reducing and optimizing cloud spending, while ensuring optimal resource utilization and maintaining desired performance levels. It ultimately involves managing cloud costs without compromising business objectives or user experience.

Learn More

Reserved Instances

What are reserved instances?


Reserved Instances (RIs) are a pricing and capacity reservation offering provided by AWS for their EC2 (Elastic Compute Cloud) and RDS (Relational Database Service) services.


They specifically allow users to commit to using a specific instance type in the same region for either a one or three-year term, in exchange for discounts of up to 72% – the exact discount is ultimately dependent on the commitment term, instance type, availability zone and region.


There are various types of Reserved Instances available, each with different terms and levels of flexibility. Standard Reserved Instances provide the highest cost savings but are the least flexible, whereas Convertible Reserved Instances offer more flexibility by allowing you to change instance families within the same instance type.


In contrast, Scheduled Reserved Instances offer a lower discount, but allow you to reserve capacity for specific time windows, such as business hours or weekends, providing cost savings for predictable workloads.

Learn More

Tail Spend

What is tail spend?


Tail spend refers to the unmanaged purchases made within an organization that fail to pass through an official procurement process. On account of their low value, the costs incurred by these purchases are seldom monitored by financing teams as they are generally too small to be deemed “strategic”. The problem, however, is that they can make up as much as 20% of a business’ total spend.

Learn More

SaaS Sprawl

What is SaaS sprawl?


SaaS sprawl, also known as software sprawl, occurs when an organization’s SaaS stack consists of a large — and often unmanageable — number of applications.


Ultimately, as business needs grow, the number of digital tools required increases, which leads to new applications being subscribed to, be this through a centralized process or at the will of individual employees.

Learn More

Reduction Clause

What is a reduction clause?


A reduction clause refers to a provision in a software agreement that allows customers to reduce the number of licenses or users covered by their subscription during the term of an agreement. This provides customers with flexibility to adjust their plan to meet evolving business needs, while avoiding paying for licenses or users they no longer require or needing to terminate the contract. The specific terms and requirements of a reduction clause may vary depending on the SaaS provider and the subscription agreement, for example it may be subject to a minimum number of licenses or users.

Learn More

SaaS Management

What is SaaS management?


SaaS management is the process of identifying, managing, and governing the software applications that exist within an organization’s technology portfolio.


When software goes unmanaged, it not only puts the business at risk of data breaches and security issues, but it can also lead to a substantial amount of wasted spend as a result of redundant and duplicate SaaS apps, not to mention unused licenses.

Learn More