Orchestration is the automated arrangement, coordination, and management of multiple, complex computer systems, services, and software to execute a cohesive workflow. The question describes handling "complex and distributed operations" programmatically as a single process, which is the core function of orchestration. It goes beyond simple automation by coordinating multiple automated tasks across different systems or services to achieve a larger, business-oriented goal, such as deploying a multi-tier application.

B. Provisioning: This is the process of creating and deploying a specific resource (e.g., a virtual machine or storage), which is often just one step within a larger orchestrated workflow.

C. Automation: This is a broad term for making a single task or process run without human intervention. Orchestration is a specific, higher-level form of automation that coordinates multiple automated tasks.

D. Allocation: This refers to the assignment of specific computational resources (like CPU or RAM) to a provisioned service. It is a granular action and a subset of provisioning.

1. National Institute of Standards and Technology (NIST). (2011). NIST Cloud Computing Reference Architecture (NIST Special Publication 500-292). Section 5.3.1

"Service Orchestration

" states

"The Service Orchestration refers to the composition of system components to provide a Cloud service to a Cloud Consumer. It includes arranging

coordinating

and managing the components to provide the service."

2. National Institute of Standards and Technology (NIST). (2017). Application Container Security Guide (NIST Special Publication 800-190). Section 3.2

"Orchestrators

" describes how orchestrators are used to manage complex applications composed of many containers

handling tasks like scheduling

load balancing

and service discovery

which exemplifies the coordination of distributed operations.

3. Mell

P.

& Grance

T. (2011). The NIST Definition of Cloud Computing (NIST Special Publication 800-145). The characteristic of "On-demand self-service" is described as a consumer being able to "unilaterally provision computing capabilities... automatically without requiring human interaction." Orchestration is the mechanism that enables the automated coordination required for complex provisioning.

4. Papazoglou

M. P.

& van den Heuvel

W. J. (2011). Service orchestration and choreography. In Web Services Foundations (pp. 319-365). Springer

Berlin

Heidelberg. This academic text distinguishes orchestration as the coordination of multiple services to achieve a composite task

managed from a central point of control

which aligns with the question's scenario. (DOI: 10.1007/978-3-642-19576-510)