Cloud Concepts is the foundational domain of the AZ-900 exam, designed to introduce you to the core ideas behind cloud computing. In plain English, this domain covers what the cloud is, how it works, and why businesses are moving to it. You'll learn about the different cloud service models (IaaS, PaaS, SaaS) and deployment models (public, private, hybrid). Think of it like understanding the difference between owning a car (on-premises), leasing one (IaaS), taking a taxi (PaaS), or riding a bus (SaaS). Each has trade-offs in control, cost, and maintenance.
Why is this important for real-world IT work? Because cloud computing is now the default for most organizations. Whether you're a system administrator, developer, or security analyst, you'll need to understand concepts like scalability (adding resources when demand spikes), elasticity (automatically scaling up and down), and high availability (keeping services running even if a server fails). For example, an e-commerce site uses cloud elasticity to handle Black Friday traffic without crashing. Without these concepts, you can't design cost-effective, resilient systems.
The exam tests your ability to define and compare these concepts, not to implement them. You'll see questions like 'Which cloud model gives you the most control?' (IaaS) or 'What is a benefit of public cloud?' (pay-as-you-go pricing). You need to know the differences between CapEx (buying hardware upfront) and OpEx (paying for what you use), and understand that the cloud shifts costs from CapEx to OpEx. Also, know the shared responsibility model: the cloud provider secures the infrastructure, but you secure your data and applications.
To study, start by memorizing the definitions and examples for each model and concept. Use mnemonics: IaaS = 'Infrastructure as a Service' = you manage the OS and apps; PaaS = 'Platform as a Service' = you only manage apps; SaaS = 'Software as a Service' = you just use it. Then, practice with sample questions to see how these concepts are applied in scenarios. Focus on why a company would choose one model over another. For instance, a startup might prefer PaaS to avoid managing servers. Finally, understand the trade-offs in cost, control, and responsibility. This domain is the easiest to score high on if you master the vocabulary.
Courseiva uses original exam-style practice questions designed for learning and revision. The goal is to understand the concepts, recognise exam patterns, and improve through explanations — not memorise copied exam dumps.
Cloud Concepts covers the fundamental principles of cloud computing, including service models (IaaS, PaaS, SaaS), deployment models (public, private, hybrid), and key concepts like scalability, elasticity, high availability, and the shared responsibility model.
Define and compare IaaS, PaaS, and SaaS with examples
Describe public, private, and hybrid cloud deployment models
Explain the shared responsibility model and who secures what
Differentiate between CapEx and OpEx and how cloud shifts costs
Identify benefits of cloud computing like scalability, elasticity, and high availability
Understand consumption-based pricing and its advantages
Watch out for
Common Describe cloud concepts exam traps
▸Confusing IaaS with PaaS: IaaS gives you control over the OS and apps; PaaS only over apps
▸Thinking public cloud is always cheaper than on-premises (it depends on workload)
▸Mixing up scalability (adding resources) with elasticity (automatic scaling)
▸Assuming the cloud provider is responsible for all security (shared responsibility model)
Practice set
Describe cloud concepts questions
20 questions · select your answer, then reveal the explanation
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?
Trap 1: High availability
High availability ensures that services remain accessible during failures, but it does not inherently provide automatic scaling.
Trap 2: Disaster recovery
Disaster recovery focuses on recovering from catastrophic failures, not on scaling resources dynamically.
Trap 3: Fault tolerance
Fault tolerance allows a system to continue operating after component failures, but it does not automatically adjust capacity.
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?
Trap 1: Scalability
Scalability is about adjusting resources to handle load, not about maintaining availability during failures.
Trap 2: Elasticity
Elasticity is automatic scaling, not fault tolerance.
Trap 3: Disaster recovery
Disaster recovery involves restoring services after a major outage, not preventing downtime during a failure.
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?
Trap 1: Encrypting customer data at rest
Encryption at rest is generally the customer's responsibility unless using platform-managed keys where the provider may manage the keys, but the customer must configure it.
Trap 2: Patching virtual machines
Patching VMs is the customer's responsibility in IaaS; the provider patches the host, not the VM.
Trap 3: Managing customer access policies
Access policies are managed by the customer to control who can access resources.
Why wrong: Encryption at rest is generally the customer's responsibility unless using platform-managed keys where the provider may manage the keys, but the customer must configure it.
B
Patching virtual machines
Why wrong: Patching VMs is the customer's responsibility in IaaS; the provider patches the host, not the VM.
C
Physical network security
The cloud provider is responsible for the security of the physical network, including firewalls and infrastructure against physical threats.
D
Managing customer access policies
Why wrong: Access policies are managed by the customer to control who can access resources.
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?
Trap 1: Broad network access
Broad network access refers to the ability to access resources over the network, not energy efficiency.
Trap 2: On-demand self-service
On-demand self-service allows users to provision resources without human interaction, but does not directly reduce carbon footprint.
Trap 3: Rapid elasticity
Elasticity helps scale resources to demand, but the sustainability benefit comes from pooling.
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?
Trap 1: Infrastructure as a Service (IaaS)
IaaS provides virtualized hardware, but the customer manages the operating system and applications.
Trap 2: Platform as a Service (PaaS)
PaaS provides a development platform; the customer still develops or deploys applications.
Trap 3: Function as a Service (FaaS)
FaaS is a serverless compute model for executing code, not a full application.
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?
Trap 1: Public cloud
Public cloud can have data centers in many countries, but the provider's infrastructure may not guarantee data stays within borders without specific region selection and policy enforcement.
Trap 2: Hybrid cloud
Hybrid cloud combines public and private, which could complicate data residency.
Trap 3: Community cloud
Community cloud is shared by several organizations with similar concerns, but it may not provide the strict control needed for data residency.
Why wrong: Public cloud can have data centers in many countries, but the provider's infrastructure may not guarantee data stays within borders without specific region selection and policy enforcement.
B
Private cloud
A private cloud is dedicated to a single organization, providing maximum control over data location and compliance.
C
Hybrid cloud
Why wrong: Hybrid cloud combines public and private, which could complicate data residency.
D
Community cloud
Why wrong: Community cloud is shared by several organizations with similar concerns, but it may not provide the strict control needed for data residency.
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?
Trap 1: Infrastructure as a Service (IaaS)
IaaS provides virtualized computing resources; the user is responsible for managing the OS, middleware, and applications.
Trap 2: Platform as a Service (PaaS)
PaaS provides a managed hosting environment for custom applications; the user still develops and manages the application code.
Trap 3: Functions as a Service (FaaS)
FaaS is a subset of PaaS for executing individual functions in response to events; it is not a full application delivery model.
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?
Trap 1: Public cloud
Public cloud infrastructure is shared across customers, with the provider managing physical locations; control over location is limited.
Trap 2: Hybrid cloud
Hybrid cloud combines public and private clouds; if the private portion is not dedicated, it may not provide the isolation required.
Trap 3: Community cloud
Community cloud is shared among several organizations with similar needs, not dedicated to a single entity.
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?
Trap 1: Scalability
Scalability is the ability to handle growth, but it may involve manual scaling; elasticity is specifically automatic scaling.
Trap 2: High availability
High availability ensures the application remains accessible during failures, not automatic scaling based on demand.
Trap 3: Fault tolerance
Fault tolerance ensures the system continues operating despite component failures, not scaling based on load.
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?
Trap 1: Measured service
Measured service is the metering and reporting of resource usage, which enables consumption-based billing, but the term 'consumption-based pricing' directly describes the billing model.
Trap 2: Rapid elasticity
Rapid elasticity refers to scaling resources up/down quickly, not the billing model.
Trap 3: Resource pooling
Resource pooling is the provider's ability to serve multiple customers from shared resources, not a billing model.
This model allows you to pay only for the resources you use, converting capital expenditure to operational expenditure.
B
Measured service
Why wrong: Measured service is the metering and reporting of resource usage, which enables consumption-based billing, but the term 'consumption-based pricing' directly describes the billing model.
C
Rapid elasticity
Why wrong: Rapid elasticity refers to scaling resources up/down quickly, not the billing model.
D
Resource pooling
Why wrong: Resource pooling is the provider's ability to serve multiple customers from shared resources, not a billing model.
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?
Trap 1: From operational expenditure (OpEx) to capital expenditure (CapEx)
Moving to cloud reduces CapEx and increases OpEx, not the other way around.
Trap 2: From direct expenditure to indirect expenditure
This is not a standard classification in cloud economics; the correct terms are CapEx and OpEx.
Trap 3: From variable expenditure to fixed expenditure
Cloud shifts fixed upfront costs to variable usage-based costs, so it's the opposite.
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?
Trap 1: High Availability
High availability focuses on keeping services running despite failures, not on automatic scaling based on demand.
Trap 2: Scalability
Scalability is the ability to handle growth, but it may involve manual capacity planning and does not imply automatic scaling.
Trap 3: Load Balancing
Load balancing distributes traffic across resources but does not automatically change the number of resources.
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?
Trap 1: Infrastructure as a Service (IaaS)
IaaS provides virtualized computing resources like VMs and storage; the user manages the OS and applications.
Trap 2: Platform as a Service (PaaS)
PaaS provides a platform for developing and deploying applications, but the user still develops and manages the application code.
Trap 3: Anything as a Service (XaaS)
XaaS is a general term for anything delivered as a service, but it is not a specific model like SaaS.
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?
Trap 1: Public cloud
In a public cloud, all resources are owned and operated by the cloud provider, which may not meet data residency requirements.
Trap 2: Private cloud
A private cloud is dedicated to a single organization, often on-premises, but it does not leverage public cloud services for less sensitive workloads.
Trap 3: Community cloud
Community cloud is shared by several organizations with common concerns; it is not specific to mixing on-premises and public cloud.
Why wrong: In a public cloud, all resources are owned and operated by the cloud provider, which may not meet data residency requirements.
B
Private cloud
Why wrong: A private cloud is dedicated to a single organization, often on-premises, but it does not leverage public cloud services for less sensitive workloads.
C
Hybrid cloud
Hybrid cloud connects on-premises and public cloud environments, allowing data and applications to be shared and placed where appropriate.
D
Community cloud
Why wrong: Community cloud is shared by several organizations with common concerns; it is not specific to mixing on-premises and public cloud.
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?
Trap 1: Operational expenditure to Capital expenditure
This is the reverse; moving to the cloud typically goes from CAPEX to OPEX.
Trap 2: Direct cost to Indirect cost
These are accounting terms not directly related to cloud pricing models.
Trap 3: Fixed cost to Variable cost
While cloud costs are variable, the core shift is from capital to operational expenditure.
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?
Trap 1: A) Infrastructure as a Service (IaaS)
IaaS requires you to manage the virtual machines, not focusing solely on code.
Trap 2: C) Software as a Service (SaaS)
SaaS provides ready-made software, not a platform for custom application deployment.
Trap 3: D) Functions as a Service (FaaS)
FaaS is for event-driven functions, not for a full web application.
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?
Trap 1: A) High availability
High availability ensures applications remain accessible, not directly about energy consumption.
Trap 2: B) Scalability
Scalability allows handling growth, but doesn't directly address carbon footprint.
Trap 3: D) Elasticity
Elasticity refers to automatic scaling, not environmental impact.
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?
Trap 1: A) Scalability
Scalability is about handling increased load, not regional disaster recovery.
Trap 2: B) Elasticity
Elasticity allows dynamic scaling, not specifically for disasters.
Trap 3: C) High availability
High availability typically covers failures within a datacenter or region, not a full regional outage.
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?
Trap 1: A) Reserved capacity
Reserved capacity requires a one- or three-year commitment for a discount, not pay-per-use without upfront costs.
Trap 2: C) Spot pricing
Spot pricing offers discounted capacity but instances can be evicted; not a guaranteed per-usage model.
Trap 3: D) Hybrid benefit
Hybrid benefit reduces cost by using on-premises licenses, not a pricing model for pay-per-use.
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?
Trap 1: High availability
High availability ensures that services remain operational with minimal downtime, usually through redundancy. It does not specifically address dynamic scaling of capacity based on demand.
Trap 2: Reliability
Reliability is the ability of a system to recover from failures and continue to function. It is not primarily about scaling to meet changing demand.
Trap 3: Fault tolerance
Fault tolerance enables a system to continue operating even when components fail. It does not address scaling resources based on demand.
Why wrong: High availability ensures that services remain operational with minimal downtime, usually through redundancy. It does not specifically address dynamic scaling of capacity based on demand.
B
Elasticity
Elasticity is the ability to automatically scale resources up or out (and down or in) according to workload demand, thereby aligning cost with usage. This is exactly what the scenario describes.
C
Reliability
Why wrong: Reliability is the ability of a system to recover from failures and continue to function. It is not primarily about scaling to meet changing demand.
D
Fault tolerance
Why wrong: Fault tolerance enables a system to continue operating even when components fail. It does not address scaling resources based on demand.
What does the AZ-900 exam test about Describe cloud concepts?
Cloud Concepts covers the fundamental principles of cloud computing, including service models (IaaS, PaaS, SaaS), deployment models (public, private, hybrid), and key concepts like scalability, elasticity, high availability, and the shared responsibility model.
How should I use these practice questions?
Select your answer before revealing the explanation. Then read why each option is right or wrong — this active recall approach builds retention far faster than re-reading notes.
Can I practise just Describe cloud concepts questions in a focused session?
Yes — the session launcher on this page draws every question from the Describe cloud concepts domain. Use a 10-question session first to gauge your baseline, then move to 20 or 30 once the weak spots are clear.
Where can I practise other AZ-900 topics?
Use the topic links above to move to related areas, or go back to the AZ-900 question bank to see all topics.
Are these real exam questions or dumps?
These are original practice questions written to test the same concepts the AZ-900 exam covers. They are not copied from any real exam or dump site.