The CCSK v5.0 Study Guide defines cloud computing based on the NIST SP 800-145 definition, which outlines five essential characteristics: on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service. Two key capabilities that underpin these characteristics areabstractionand resource pooling.
* Abstractionrefers to the virtualization layer that hides the underlying physical infrastructure, allowing users to interact with resources (e.g., compute, storage, networking) without needing to manage the hardware directly.
* Resource poolingenables the provider's computing resources to be pooled to serve multiple consumers using a multi-tenant model, with resources dynamically assigned and reassigned based on demand.
From theCCSK v5.0 Study Guide, Domain 1 (Cloud Computing Concepts and Architectures), Section
1.2:
"Cloud computing relies on abstraction to simplify the user experience and resource pooling to efficiently allocate resources across multiple tenants. Resource pooling is a defining characteristic, where the provider's computing resources are pooled to serve multiple consumers, with different physical and virtual resources dynamically assigned and reassigned according to consumer demand." Option B correctly identifiesabstraction and resource poolingas the two key capabilities.
* Option A (Abstraction and orchestration) is incorrect because orchestration, while important for automation, is not a defining characteristic of cloud computing.
* Option C (Multi-tenancy and isolation) is incorrect because, while multi-tenancy is a feature of resource pooling, isolation is a security mechanism, not a core capability of cloud computing.
* Option D (Virtualization and multi-tenancy) is incorrect because virtualization is a technology that enables abstraction, but multi-tenancy alone is not sufficient to define cloud computing.
References:
CCSK v5.0 Study Guide, Domain 1, Section 1.2: Cloud Computing Definitions and Characteristics.
NIST SP 800-145: The NIST Definition of Cloud Computing.