The concept described is "Measured service," one of the five essential characteristics of cloud computing defined by the National Institute of Standards and Technology (NIST). This characteristic enables the cloud provider to automatically control and optimize resource usage by leveraging a metering capability. Resource consumption (such as storage, processing, bandwidth, and active user accounts) is monitored, controlled, and reported. This provides transparency for both the provider and the consumer and is the foundation for the pay-per-use or pay-as-you-go business model, where customers are billed only for the resources they actually consume.

A. Consumable service: This is a generic description, not the specific, standardized term for the cloud's pay-per-use billing and resource management model.

C. Billable service: This term is too broad. It simply indicates that a service has a cost, but it does not describe the specific model of charging based on measured usage.

D. Metered service: While metering is the mechanism that enables a measured service, "Measured service" is the official NIST term for the overall characteristic and concept.

1. Mell

P.

& Grance

T. (2011). The NIST Definition of Cloud Computing (Special Publication 800-145). National Institute of Standards and Technology. Retrieved from https://doi.org/10.6028/NIST.SP.800-145.

Page 2

Section 2

"Essential Characteristics": "Measured service. Cloud systems automatically control and optimize resource use by leveraging a metering capability... Resource usage can be monitored

controlled

and reported

providing transparency for both the provider and consumer of the utilized service."

2. Armbrust

M.

Fox

A.

Griffith

R.

Joseph

A. D.

Katz

R.

Konwinski

A.

... & Zaharia

M. (2010). A view of cloud computing. Communications of the ACM

53(4)

50-58. (Referenced in UC Berkeley courseware).

Page 51

Section 3

"Classes of Utility Computing": The paper discusses pay-for-use models as a defining feature of utility computing

the precursor concept to modern cloud services

stating

"users can pay for a portion of a service." This aligns with the principle of measured service.

3. Rittinghouse

J. W.

& Ransome

J. F. (2017). Cloud Computing: Implementation

Management

and Security. CRC Press. (Widely used as a university textbook).

Chapter 2

"The Cloud Defined": This chapter explicitly details the NIST definition

explaining that "Measured Service is what makes the pay-per-use model of cloud computing possible."