AZ-900 Microsoft Azure Fundamentals Exam
Start here! Get your feet wet with the Microsoft cloud and begin your journey to earning your Microsoft Certified: Azure Fundamentals certification!
Gauge your current knowledge

Gauge your current knowledge

Start here! Get your feet wet with the Microsoft cloud and begin your journey to earning your Microsoft Certified: Azure Fundamentals certification!
Gauge your current knowledge

Gauge your current knowledge

Software as a Service (SaaS) provides users with ready-to-use applications over the internet. You pay a recurring subscription fee, and the provider handles everything from updates to security patches. Because the application runs on the provider’s servers, you can access it from any device with a browser—no local installation needed. This model works best for services where ease of access and minimal management are priorities.
SaaS offers automatic updates managed by the provider, so your software is always current. It is highly accessible from anywhere and scales easily as your user base grows. These features make it ideal for organizations that want to avoid the work of maintaining their own hardware or software.
Common use cases include email services like Microsoft Outlook, customer relationship management (CRM) tools such as Salesforce, and collaboration platforms like Microsoft Teams or Slack. These applications support remote work and global teams without requiring on-premises infrastructure. The trade-off is that you depend on internet connectivity and must trust the provider with your data, which can raise security and compliance concerns.
Platform as a Service (PaaS) gives developers a managed hosting environment where they can build and deploy applications without worrying about the underlying infrastructure. Azure handles patching, backups, and scaling, so you focus on writing code. Azure services such as Azure SQL Database and Azure Logic Apps are examples of PaaS offerings that simplify development and integration.
PaaS reduces operational overhead because Azure manages the infrastructure. Services automatically scale to meet demand, maintaining performance and availability. Integrated development tools—like prebuilt connectors in Azure Logic Apps—speed up the creation of workflows and connections to other services.
PaaS is well suited for web application hosting using Azure App Service, API management with Azure API Management, and data analytics via Azure SQL Database. These scenarios benefit from built-in scaling, security, and high availability. For example, Azure SQL Database offers intelligent query processing and flexible deployment options such as single databases or elastic pools.
Azure Logic Apps lets you create automated workflows that link applications, data, and services. With over 1,400 connectors, you can integrate Azure and third-party tools to automate business processes. The service scales to handle large transaction volumes, adapting to changing business needs without manual intervention.
Infrastructure as a Service (IaaS) provides fundamental computing resources such as virtual machines (VMs), storage, and networking. Azure supplies the physical hardware, but you manage the operating system, applications, and runtime. You pay only for what you use and can scale up or down as needed, giving you full control over the environment.
Key components include virtual machines for full OS control, storage accounts like Azure Disks and Blob storage, and virtual networks with load balancers for secure connectivity. You configure these resources similarly to on-premises servers but with the agility of the cloud. Azure handles core platform reliability, but you are responsible for resilience, backups, and scaling rules.
IaaS is ideal for lift-and-shift migrations of existing applications with minimal code changes, disaster recovery by replicating VMs across regions, and development and testing environments that you can create and destroy on demand. This model fits scenarios where you need custom configurations or have legacy workloads that cannot run on PaaS or SaaS. The trade-off is higher administrative overhead for updates, patches, and security.
In a public cloud deployment, Azure owns and manages the physical infrastructure, and you share it with other customers. This model gives you elasticity—resources scale automatically to match demand—and global reach, because Azure datacenters are located around the world. Public cloud is best when you need to quickly ramp up capacity without investing in hardware, such as for variable-traffic web applications or batch data processing. Because the infrastructure is shared, costs are typically lower, but you have less control over the physical environment.
A private cloud environment uses dedicated resources that are not shared with other organizations. This model gives you enhanced control over infrastructure, networking, and data, which is critical for meeting strict regulatory requirements or handling sensitive information. You can host a private cloud in your own datacenter or use a dedicated Azure solution such as Azure Stack. Choose a private cloud when you need dedicated resources and specific regulatory adherence, and when data sovereignty or compliance mandates that your workloads stay isolated from other tenants.
A hybrid cloud combines a public cloud with a private cloud or on-premises infrastructure, allowing data and applications to move between them. This strategy extends your on-premises capabilities into the cloud, provides data portability, and helps manage fluctuating workloads—you can run steady workloads on-premises and burst into the public cloud during peak demand. Hybrid cloud is useful when you have legacy systems that cannot move entirely to the cloud, or when you need to keep certain data on-site for compliance but still benefit from cloud scalability. Azure services like Azure Arc and Azure VPN Gateway help connect and manage these environments together.
When selecting between public, private, and hybrid cloud, consider your organization’s data sovereignty requirements, application performance needs, and operational agility. For example, a startup needing fast global scale with low upfront cost might choose public cloud. A hospital that must store patient records on-premises for compliance might prefer a private cloud or hybrid approach. A manufacturing company with variable workloads might use hybrid to keep steady systems local and burst to the public cloud for spikes. The right choice balances control, cost, and flexibility based on your specific business goals.
Each cloud model carries different security and compliance responsibilities. In IaaS, you manage the OS and applications, so you must handle patching, access controls, and antivirus yourself. PaaS shifts some of that burden to Azure, which manages the platform security. SaaS puts most security in the provider’s hands, but you still control user access and data governance.
Azure offers tools like Microsoft Defender for Cloud to monitor threats, Azure Firewall for network protection, and Azure DDoS Protection to guard against attacks. These services integrate with your chosen cloud model. For identity management, Azure Active Directory provides single sign-on and multi-factor authentication, and Microsoft Entra ID Protection detects suspicious activity.
Azure holds certifications such as ISO 27001, HIPAA, and GDPR to help you meet industry-specific regulations. Understanding which certifications apply to your workload is essential. For example, a healthcare application may require HIPAA compliance, which influences whether you use IaaS, PaaS, or SaaS and how you configure data storage and access.
Cost and management responsibility vary across the three service models. IaaS gives you full control, but you pay for each VM, storage transaction, and network egress, often per hour. You handle OS updates and backups, which adds administrative overhead. Use Azure Reservations or Savings Plans to reduce costs if you commit to long-term usage.
PaaS lowers administrative work because Azure manages the platform. You are charged based on service tiers and usage metrics rather than individual VMs. This model reduces overhead but may require you to choose the right tier and scaling settings to control costs.
SaaS has the lowest management burden; you pay a predictable subscription fee per user or feature. The trade-off is less flexibility and reliance on the provider’s update schedule. Across all models, use the Azure pricing calculator to forecast costs, and implement budgets, alerts, and resource tags to monitor spending. The choice of cloud model directly affects your budget, resource allocation, and the administrative effort your team must invest.