MS-900 Describe cloud concepts — 10 Questions

Question 1

A company is evaluating moving its on-premises infrastructure to a cloud environment. They want a service that provides virtual machines, storage, and networking capabilities while retaining full control over the operating system and applications. Which cloud service model best meets this requirement?

Accepted Answer

Infrastructure as a Service (IaaS). Infrastructure as a Service (IaaS) provides virtualized computing resources, including virtual machines, storage, and networking, over the internet. The customer retains full administrative control over the operating system, applications, and middleware, while the cloud provider manages the underlying physical hardware. This matches the requirement for full OS and application control.

Answer

Software as a Service (SaaS)

Answer

Platform as a Service (PaaS)

Answer

Private Cloud

Question 2

Which characteristic of cloud computing allows a user to provision resources automatically without requiring human interaction with the service provider?

Accepted Answer

On-demand self-service. Option C is correct because on-demand self-service is a fundamental characteristic of cloud computing defined by NIST (SP 800-145) that allows a user to unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service provider. This is typically implemented through a web portal or API (e.g., AWS Console, Azure Portal, or RESTful APIs) that enables instant resource creation and configuration.

Answer

Rapid elasticity

Answer

Resource pooling

Answer

Measured service

Question 3

A company runs a critical application on-premises but wants to extend capacity to the cloud during peak demand without purchasing additional hardware. Which cloud deployment model best describes this strategy?

Accepted Answer

Hybrid cloud. A hybrid cloud model combines on-premises infrastructure (private cloud) with public cloud resources, enabling a company to 'burst' into the public cloud during peak demand without purchasing additional hardware. This strategy, often called cloud bursting, allows the critical application to run locally under normal conditions and seamlessly extend capacity to a public cloud provider like Azure during spikes.

Answer

Public cloud

Answer

Private cloud

Answer

Multi-cloud

Question 4

A company's CFO is pleased that they only pay for the compute and storage resources consumed each month, with no upfront hardware costs. This billing model is a direct result of which cloud computing characteristic?

Accepted Answer

Measured service. The CFO's observation that the company only pays for consumed compute and storage resources with no upfront hardware costs directly reflects the 'measured service' characteristic of cloud computing. Measured service means cloud providers meter resource usage (e.g., CPU hours, GB-months of storage) and bill based on actual consumption, typically using a pay-as-you-go model. This eliminates the need for capital expenditure on hardware, as costs are operational and tied to usage metrics.

Answer

On-demand self-service

Answer

Broad network access

Answer

Resource pooling

Question 5

A startup wants to focus only on developing and deploying its application code without managing underlying servers or operating systems. Which cloud service model best fits this need?

Accepted Answer

Platform as a Service (PaaS). Platform as a Service (PaaS) is the correct choice because it abstracts the underlying infrastructure, including servers, operating systems, and runtime environments, allowing the startup to focus solely on developing and deploying application code. With PaaS, the cloud provider manages the OS patching, hardware scaling, and middleware, while the customer only manages the application and data. This directly matches the requirement of not managing servers or operating systems.

Answer

Infrastructure as a Service (IaaS)

Answer

Software as a Service (SaaS)

Answer

On-premises deployment

Question 6

An e-commerce application runs in the cloud and automatically adjusts the number of virtual machines based on real-time traffic. When traffic spikes, more VMs are added; when traffic drops, VMs are removed. Which cloud computing characteristic does this behavior exemplify?

Accepted Answer

Rapid elasticity. Rapid elasticity is the cloud characteristic that enables resources to scale out (add VMs) and scale in (remove VMs) automatically in response to real-time demand. In this e-commerce scenario, the application adjusts VM count based on traffic spikes and drops, which directly matches the definition of rapid elasticity as defined by NIST SP 800-145.

Answer

Measured service

Answer

Resource pooling

Answer

On-demand self-service

Question 7

A company runs a legacy application that requires a fixed amount of dedicated hardware resources for compliance reasons. However, they want to benefit from cloud-based backup and disaster recovery to reduce on-premises hardware costs. Which cloud deployment model best aligns with this requirement?

Accepted Answer

Hybrid cloud. Hybrid cloud is correct because it allows the company to keep the legacy application on dedicated on-premises hardware for compliance, while leveraging cloud-based backup and disaster recovery services (e.g., Azure Backup and Azure Site Recovery) to reduce on-premises hardware costs. This model combines private cloud (or on-premises infrastructure) with public cloud resources, enabling data replication and failover to the cloud without migrating the application itself.

Answer

Public cloud

Answer

Private cloud

Answer

Community cloud

Question 8

Which cloud deployment model provides the highest level of control over resources and infrastructure?

Accepted Answer

Private cloud. The private cloud deployment model provides the highest level of control over resources and infrastructure because it is dedicated to a single organization, allowing full customization of hardware, networking, and security policies. Unlike public or hybrid models, the organization retains exclusive administrative access and can enforce strict compliance requirements without sharing underlying physical resources with other tenants.

Answer

Public cloud

Answer

Hybrid cloud

Answer

Community cloud

Question 9

A company migrates its database to Azure SQL Database (PaaS). According to the shared responsibility model, which of the following is the customer's responsibility?

Accepted Answer

Managing user access and authentication. In the shared responsibility model for Azure SQL Database (PaaS), the customer is responsible for managing user access and authentication because the customer controls who can connect to the database and what permissions they have. Microsoft manages the underlying infrastructure, including the operating system, physical hardware, and virtualization layer, while the customer must secure data access through Azure Active Directory or SQL authentication, configure firewall rules, and manage logins and users.

Answer

Patching the operating system of the database server

Answer

Maintaining the physical infrastructure

Answer

Managing the virtualization layer

Question 10

A cloud provider offers virtual machines, but customers must install, configure, and maintain the operating system and applications. Which cloud service model does this describe?

Accepted Answer

IaaS (Infrastructure as a Service). This scenario describes Infrastructure as a Service (IaaS), where the cloud provider supplies virtualized computing resources such as virtual machines, storage, and networking, but the customer retains full control over the operating system, middleware, and applications. In IaaS, the provider manages only the physical infrastructure (hypervisor, servers, storage, and network), while the customer is responsible for OS installation, configuration, patching, and application management. This aligns directly with the question's description of customer-managed OS and applications on provider-hosted VMs.

Answer

PaaS (Platform as a Service)

Answer

SaaS (Software as a Service)

Answer

FaaS (Function as a Service)