Infrastructure as a Service (IaaS) is the cloud service model that provides virtualized computing resources over the internet. With IaaS, the consumer can provision fundamental resources like processing (virtual machines), storage, and networks. The key characteristic that fits the company's needs is that the consumer has control over the operating systems, storage, and deployed applications. This allows the company to choose and configure the OS on each virtual machine, which is not possible with other models like PaaS or SaaS where the provider manages the OS.

A. Function as a Service (FaaS): This is a serverless model for running event-triggered code. The user does not manage or even see the underlying virtual machines or operating systems.

C. Platform as a Service (PaaS): The provider manages the underlying infrastructure, including the operating systems. The customer only manages their applications and data, not the OS configuration.

D. Software as a Service (SaaS): This model delivers a complete software application. The user has no control over the infrastructure, platform, or OS; they only use the provided software.

1. Mell

P.

& Grance

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

Page 2

Section "Service Models": Defines Infrastructure as a Service (IaaS) as providing the capability to "provision processing

storage

networks

and other fundamental computing resources where the consumer is able to deploy and run arbitrary software

which can include operating systems and applications... The consumer... has control over operating systems

storage

and deployed applications." This directly supports the selection of IaaS.

2. Armbrust

M.

Fox

A.

Griffith

R.

Joseph

A. D.

Katz

R.

Konwinski

A.

... & Zaharia

M. (2009). Above the Clouds: A Berkeley View of Cloud Computing (Technical Report No. UCB/EECS-2009-28). EECS Department

University of California

Berkeley.

Page 3

Section 2.1 "Classes of Utility Computing": Describes IaaS providers as offering "virtual machines (VMs) and storage." It contrasts this with PaaS

where the provider manages the OS and servers

and SaaS

which provides complete applications. This academic source confirms that control over VMs and their OS is a defining feature of IaaS.

3. Microsoft Azure Documentation. (n.d.). What is IaaS?. Microsoft. Retrieved from the official Microsoft Azure website.

Section "What is IaaS?": States

"The cloud computing service provider manages the infrastructure

while you purchase

install

configure

and manage your own software—operating systems

middleware

and applications." This official vendor documentation aligns with the company's requirement to choose and configure operating systems.