AZ-900 Describe cloud concepts — 40 Questions

Question 1

A startup wants to deploy a web application that experiences unpredictable traffic spikes. They need to scale resources automatically without manual intervention. Which benefit of cloud computing directly addresses this requirement?

Accepted Answer

Elasticity. Elasticity is the cloud computing benefit that enables resources to automatically scale out (add instances) during traffic spikes and scale in (remove instances) when demand drops, without manual intervention. This directly matches the startup's need to handle unpredictable traffic patterns by dynamically adjusting compute capacity, typically using services like Azure Virtual Machine Scale Sets or Azure App Service auto-scale rules.

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High availability

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Disaster recovery

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Fault tolerance

Question 2

A retail company runs its e-commerce platform on a public cloud. During a major sale event, they want to ensure that the application remains accessible even if an entire data center fails. Which cloud computing concept does this describe?

Accepted Answer

High availability. Option C is correct because high availability ensures that the application remains accessible even if an entire data center fails, typically through redundant infrastructure across multiple availability zones. This is achieved by deploying the application in a load-balanced, multi-AZ configuration that automatically fails over to healthy instances, maintaining uptime despite a complete data center outage.

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Scalability

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Elasticity

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Disaster recovery

Question 3

A financial services company is evaluating a public cloud provider. They are concerned about the shared responsibility model for security. The company must ensure that their customer data is encrypted at rest and in transit. Under the shared responsibility model, which security control is the cloud provider typically responsible for?

Accepted Answer

Physical network security. Under the shared responsibility model, the cloud provider is responsible for the security OF the cloud, which includes physical network security such as protecting the data center perimeter, network infrastructure, and hardware. This is correct because physical security controls (e.g., access badges, surveillance, and network firewalls at the provider's edge) are entirely the provider's domain and cannot be delegated to the customer.

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Encrypting customer data at rest

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Patching virtual machines

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Managing customer access policies

Question 4

A multinational corporation wants to reduce its carbon footprint by shifting workloads to the cloud. They want to understand how using a cloud provider's shared infrastructure contributes to sustainability. Which cloud computing concept is most directly related to this environmental benefit?

Accepted Answer

Resource pooling. Resource pooling is the cloud computing concept most directly related to sustainability because it allows a cloud provider to serve multiple customers from the same shared physical infrastructure. By dynamically allocating and reallocating resources based on demand, the provider maximizes utilization rates, reducing the total number of physical servers and data centers needed. This consolidation directly lowers energy consumption and carbon emissions per workload, which is the core environmental benefit of shifting to the cloud.

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Broad network access

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On-demand self-service

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Rapid elasticity

Question 5

A small business wants to move its accounting software to the cloud to avoid purchasing and maintaining physical servers. Which cloud service model would provide the accounting application as a ready-to-use service over the internet?

Accepted Answer

Software as a Service (SaaS). Option C (SaaS) is correct because the business needs a ready-to-use accounting application delivered over the internet without managing underlying infrastructure. SaaS provides fully functional software accessed via a web browser, where the provider handles all maintenance, updates, and server management, aligning perfectly with the goal of avoiding physical server ownership.

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Infrastructure as a Service (IaaS)

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Platform as a Service (PaaS)

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Function as a Service (FaaS)

Question 6

A hospital is subject to strict data residency laws that require patient data to remain within the country's borders. They are considering using a public cloud provider. Which cloud deployment model would best meet this compliance requirement?

Accepted Answer

Private cloud. A private cloud is dedicated to a single organization, allowing the hospital to deploy and manage infrastructure within its own data center or a colocation facility located within the country's borders. This ensures full control over data storage and processing, directly satisfying data residency laws that prohibit patient data from leaving the country. In contrast, public cloud providers may have data centers in multiple regions, making it harder to guarantee data never crosses borders.

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Public cloud

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Hybrid cloud

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Community cloud

Question 7

A small business wants to run its accounting application without managing the underlying operating systems or hardware. The application is accessed through a web browser. Which cloud service model is being used?

Accepted Answer

Software as a Service (SaaS). The correct answer is C (SaaS) because the business uses a web browser to access the accounting application without managing the underlying OS or hardware. SaaS delivers fully functional software over the internet, where the provider handles all infrastructure, platform, and application management, matching the scenario's requirement of zero administrative overhead.

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Infrastructure as a Service (IaaS)

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Platform as a Service (PaaS)

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Functions as a Service (FaaS)

Question 8

A financial services company processes sensitive customer data and must strictly control the physical location of the servers. They want to use cloud computing but with dedicated hardware that is not shared with other customers. Which cloud deployment model should they choose?

Accepted Answer

Private cloud. A private cloud is the correct deployment model because it provides dedicated, single-tenant infrastructure that is not shared with other customers. This ensures that the financial services company can maintain strict physical control over server locations and meet compliance requirements for sensitive customer data, as the hardware is exclusively used by one organization.

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Public cloud

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Hybrid cloud

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Community cloud

Question 9

A company runs a web application that experiences sudden spikes in traffic during promotional events. They want to automatically add more virtual machines during high demand and remove them when traffic subsides, paying only for the resources used. Which cloud computing benefit does this scenario describe?

Accepted Answer

Elasticity. This scenario describes elasticity, which is the ability of a cloud system to automatically provision and de-provision resources (such as virtual machines) in response to real-time demand changes. The key phrase 'automatically add more virtual machines during high demand and remove them when traffic subsides, paying only for the resources used' directly matches the cloud computing benefit of elasticity, where scaling is dynamic and resource usage is metered, ensuring cost efficiency.

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Scalability

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High availability

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Fault tolerance

Question 10

A company is evaluating moving its on-premises applications to the cloud. The IT manager wants to avoid upfront hardware costs and instead pay for resources on a monthly basis based on usage. Which cloud characteristic enables this financial model?

Accepted Answer

Consumption-based pricing. Consumption-based pricing is the cloud characteristic that allows organizations to pay only for the resources they actually use, such as compute hours, storage GBs, or data transfer, without any upfront hardware costs. This model shifts IT spending from a capital expenditure (CapEx) to an operational expenditure (OpEx), aligning costs directly with usage. The IT manager's requirement to avoid upfront costs and pay monthly based on usage is the exact definition of consumption-based pricing.

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Measured service

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Rapid elasticity

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Resource pooling

Question 11

A company is considering moving its IT infrastructure to the cloud. The CFO wants to understand the financial impact: instead of purchasing servers and paying for maintenance, the company will pay a monthly fee based on usage. This shift represents moving from which type of expenditure to which?

Accepted Answer

From capital expenditure (CapEx) to operational expenditure (OpEx). This shift represents moving from capital expenditure (CapEx) to operational expenditure (OpEx). CapEx involves upfront costs for physical assets like servers, which depreciate over time, while OpEx involves ongoing, usage-based payments for cloud services. In Azure, this aligns with the consumption-based model where you pay only for resources consumed (e.g., VM hours, storage GBs), eliminating large initial investments and shifting financial risk to the provider.

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From operational expenditure (OpEx) to capital expenditure (CapEx)

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From direct expenditure to indirect expenditure

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From variable expenditure to fixed expenditure

Question 12

A company wants to increase the number of virtual machines it uses during peak hours and decrease them during off-peak hours without manual intervention. Which characteristic of cloud computing does this represent?

Accepted Answer

Elasticity. Elasticity is the cloud characteristic that allows resources to automatically scale out (increase) during peak demand and scale in (decrease) during off-peak hours without manual intervention. This matches the company's requirement for dynamic, automatic adjustment of virtual machine counts based on workload changes.

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High Availability

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Scalability

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Load Balancing

Question 13

A startup wants to use a cloud-based email service without installing any software on their own computers. They access the service through a web browser and the provider manages all updates and maintenance. Which cloud service model does this represent?

Accepted Answer

Software as a Service (SaaS). This scenario describes Software as a Service (SaaS) because the startup is using a fully managed cloud-based email application accessed via a web browser, with no local installation required. The provider handles all updates, maintenance, and infrastructure, which is the defining characteristic of SaaS. Examples include Microsoft 365 or Google Workspace, where the consumer only uses the software without managing the underlying platform or infrastructure.

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Infrastructure as a Service (IaaS)

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Platform as a Service (PaaS)

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Anything as a Service (XaaS)

Question 14

A bank needs to keep some sensitive customer data on-premises due to regulatory requirements, but wants to use cloud services for less sensitive workloads. Which cloud deployment model should they adopt?

Accepted Answer

Hybrid cloud. A hybrid cloud model combines on-premises infrastructure (private cloud) with public cloud services, allowing the bank to keep sensitive customer data on-premises to meet regulatory requirements while using the public cloud for less sensitive workloads. This approach provides a unified management plane and secure connectivity (e.g., VPN or Azure ExpressRoute) between the two environments, ensuring compliance and flexibility.

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Public cloud

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Private cloud

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Community cloud

Question 15

A company is moving from an on-premises data center to Azure. Instead of paying a large upfront cost for servers, they will pay a monthly subscription fee based on usage. This represents a shift from which type of expenditure to which?

Accepted Answer

Capital expenditure to Operational expenditure. This scenario describes a shift from Capital Expenditure (CapEx) to Operational Expenditure (OpEx). CapEx involves upfront, long-term investments in physical assets like servers, while OpEx is a pay-as-you-go model where costs are incurred based on actual usage. Azure's subscription model eliminates the need for large initial capital outlays, aligning costs with consumption.

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Operational expenditure to Capital expenditure

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Direct cost to Indirect cost

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Fixed cost to Variable cost

Question 16

A startup wants to quickly deploy a web application without worrying about server maintenance. They only want to focus on writing code and deploying it. Which cloud service model best fits this requirement?

Accepted Answer

B) Platform as a Service (PaaS). Platform as a Service (PaaS) provides a managed hosting environment where the cloud provider handles the underlying infrastructure (servers, storage, networking, OS patches) while the customer focuses solely on deploying and managing their own code and data. This directly matches the startup's requirement to avoid server maintenance and concentrate on writing and deploying code.

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A) Infrastructure as a Service (IaaS)

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C) Software as a Service (SaaS)

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D) Functions as a Service (FaaS)

Question 17

A company is considering moving its on-premises workloads to the cloud. They want to reduce their carbon footprint by using a cloud provider that uses renewable energy. Which cloud computing benefit is most directly related to this goal?

Accepted Answer

C) Sustainability. Option C is correct because sustainability directly addresses the goal of reducing carbon footprint through the use of renewable energy. Cloud providers like Microsoft Azure invest in renewable energy projects and carbon offset programs, enabling customers to lower their environmental impact by consolidating workloads in energy-efficient data centers. This benefit is explicitly tied to environmental responsibility, not operational metrics like uptime or resource scaling.

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A) High availability

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B) Scalability

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D) Elasticity

Question 18

A company wants to ensure that its cloud resources are available even if a major disaster occurs in one region. They plan to deploy resources in two different geographic locations. Which cloud computing characteristic does this scenario primarily address?

Accepted Answer

D) Disaster recovery. Option D (Disaster recovery) is correct because the scenario explicitly describes deploying resources in two different geographic locations to ensure availability despite a major regional disaster. Disaster recovery (DR) focuses on restoring services and data after a catastrophic failure, often using paired regions (e.g., Azure paired regions) to provide geo-redundancy and failover capabilities. This goes beyond simple uptime guarantees to address full recovery from region-level outages.

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A) Scalability

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B) Elasticity

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C) High availability

Question 19

A company wants to pay only for the compute resources they actually use, with no upfront costs. They can scale up or down based on demand. Which cloud pricing model does this describe?

Accepted Answer

B) Pay-as-you-go. The pay-as-you-go model (also called consumption-based pricing) allows a company to pay only for the compute resources they actually consume, with no upfront costs or long-term commitments. This model provides the flexibility to scale resources up or down based on real-time demand, aligning costs directly with usage. It is the standard pricing model for most cloud services, including Azure virtual machines and App Service plans, when no reservation or spot discount is applied.

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A) Reserved capacity

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C) Spot pricing

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D) Hybrid benefit

Question 20

A company runs a seasonal e-commerce application. During holidays, traffic increases tenfold, but the company does not want to over-provision resources for the rest of the year. They want to add or remove server capacity automatically based on real-time demand and pay only for what they use. Which cloud computing characteristic does this scenario describe?

Accepted Answer

Elasticity. Elasticity is the cloud computing characteristic that enables automatic scaling of resources up or down based on real-time demand. In this scenario, the e-commerce application needs to handle a tenfold traffic increase during holidays without over-provisioning for the rest of the year, which is exactly what elasticity provides by adding or removing server capacity dynamically and charging only for what is used.

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High availability

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Reliability

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Fault tolerance