1.3 Summarize cloud concepts and connectivity options
📘CompTIA Network+ (N10-009)
Infrastructure as a Service (IaaS) – Detailed Explanation
Definition:
IaaS is a cloud service model where a provider delivers virtualized computing resources over the internet. In IaaS, the cloud provider manages the physical infrastructure, while the customer manages most of the higher-level components like operating systems, applications, and data.
Key Idea: You get hardware in the cloud as a service. Think of it as renting servers, storage, and networking without having to buy or maintain physical machines.
Components of IaaS
IaaS provides three main types of resources:
- Compute (Virtual Machines / Servers)
- Users can create virtual servers (VMs) on demand.
- Customers choose CPU, RAM, and storage size.
- The provider handles the physical hardware, power, and cooling.
- Example in IT: A company launches a VM to run a web server without buying a physical server.
- Storage
- Scalable storage space in the cloud for files, databases, and backups.
- Types of storage offered by IaaS:
- Block storage – acts like a virtual hard drive for VMs.
- Object storage – stores unstructured data like documents, images, and backups.
- File storage – shared file system accessible over the network.
- Users pay only for the storage they use.
- Networking
- Virtual networks, subnets, firewalls, and load balancers can be configured.
- Supports communication between VMs, data centers, and the internet.
- Users manage the network layout while the provider manages the underlying switches, routers, and cables.
What the Provider Manages vs. What the User Manages
| Component | Provider Responsibility | User Responsibility |
|---|---|---|
| Physical servers | ✔ | |
| Storage hardware | ✔ | |
| Networking hardware | ✔ | |
| Virtualization layer | ✔ | |
| Operating System | ✔ | |
| Applications & Software | ✔ | |
| Data | ✔ |
Key exam point: In IaaS, the provider handles hardware and virtualization, while the user handles software and data.
Benefits of IaaS
- Scalability
- Resources can be increased or decreased on demand.
- Example: During high traffic, more VMs can be added quickly.
- Cost-Effectiveness
- Pay-as-you-go model: Users only pay for what they use.
- No need to buy expensive servers.
- Flexibility
- Users can choose different OS, storage, and network configurations.
- Reduced Physical Maintenance
- No need to maintain servers, power, cooling, or physical networking.
Common IaaS Use Cases in IT
- Hosting virtual machines for applications or development environments.
- Running test or development servers that can be quickly created and destroyed.
- Storage for backups and disaster recovery.
- Big data processing with scalable compute power.
IaaS vs. Other Cloud Service Models
It’s important to compare IaaS with PaaS and SaaS for the exam:
| Service Model | Managed by Provider | Managed by User | Example |
|---|---|---|---|
| IaaS | Hardware, network, virtualization | OS, apps, data | AWS EC2, Microsoft Azure VM |
| PaaS | Hardware, OS, runtime environment | Apps, data | Google App Engine, Heroku |
| SaaS | Everything (hardware, OS, apps, runtime) | Just data/input | Gmail, Office 365 |
Tip for exam: IaaS gives the most control over computing resources compared to PaaS and SaaS, but also requires the user to manage more.
Examples of IaaS Providers
- Amazon Web Services (AWS) – EC2, S3, VPC
- Microsoft Azure – Virtual Machines, Blob Storage
- Google Cloud Platform (GCP) – Compute Engine, Cloud Storage
These services let IT professionals spin up servers, storage, and networks in minutes without touching physical hardware.
Key Exam Takeaways
- IaaS = Cloud provider manages hardware, user manages software and data.
- Provides virtualized servers, storage, and networking.
- Highly scalable, flexible, and cost-effective.
- Ideal for IT scenarios like virtual machines, backup storage, and test environments.
- Know the difference between IaaS, PaaS, and SaaS.
