Which of the following cloud characteristics makes it possible for an organization to add more servers as needed without the need to purchase additional hardware?
The cloud computing characteristic rapid elasticity provides the ability to expand or contract resources as the need or lack thereof arises. The biggest advance of this is being able to add resources faster and cheaper than adding additional hardware.
Wikipedia
Cloud computing is the on-demand availability of computer system resources, especially data storage (cloud storage) and computing power, without direct active management by the user. Large clouds often have functions distributed over multiple locations, each of which is a data center. Cloud computing relies on sharing of resources to achieve coherence and typically uses a pay-as-you-go model, which can help in reducing capital expenses but may also lead to unexpected operating expenses for users.