Which of the following is a characteristic of cloud computing?

On-demand self-service is a fundamental characteristic of cloud computing that allows users to provision resources as needed without requiring human intervention from service providers. This means that a user can access computing resources, such as storage, processing power, and applications, through a customer portal or an API at any time, scaling resources up or down according to their requirements. This capability is critical for businesses that need to adjust their resources dynamically based on changing workloads or user demand, facilitating greater flexibility and efficiency.

In contrast, fixed capacity implies a static resource allocation, which does not align with the scalable nature of cloud environments. Annual contracts suggest a rigidity that goes against the pay-as-you-go model prevalent in cloud services. Lastly, geographical limitations contradict the global reach of cloud computing, which provides access to resources from virtually anywhere with an internet connection. Thus, on-demand self-service stands out as a defining feature that enhances user autonomy and operational agility.