Cloud Computing

Master the digital infrastructure that powers modern technology

Explore Cloud Concepts

What You'll Master

Cloud computing is the foundation of modern IT. This guide delivers a clear, accessible overview of its core concepts.

Financial Models

Understanding the shift from CapEx to OpEx and cloud cost management.

Automation

Learn Infrastructure as Code and modern software delivery practices.

Security

Master the shared responsibility model and cloud security best practices.

Financial Model: CapEx vs. OpEx

Understanding the fundamental shift in IT spending from capital to operational expenditure.

Capital Expenditure (CapEx)

Traditional IT: Purchase Assets Outright

  • Fixed Cost: Large, single, upfront purchase.
  • Waste Risk: High chance of over-provisioning or under-provisioning.
  • Full Responsibility: Customer handles all maintenance and upgrades.

Operational Expenditure (OpEx)

Cloud IT: Rent as a Utility Service

  • Variable Cost: Pay-as-you-go; costs scale with usage.
  • Elasticity: Instantly scale capacity to match real-time demand.
  • Shared Responsibility: Provider manages physical hardware.

Cloud Cost Calculator

Calculate Your Potential Savings

Compare traditional CapEx spending with cloud OpEx models. Adjust the values below to see how cloud computing can transform your IT costs.

100 users
1000 GB
500 hours
Traditional CapEx
$45,000
Upfront + Maintenance
Cloud OpEx
$1,250
Monthly Cost
Annual Savings
$30,000
First Year

The Core Shift: Cloud converts fixed, risky costs into agile, variable costs, allowing your spending to directly reflect and support business activity.

Service Models

Understanding the spectrum of cloud service models from infrastructure to software.

Interactive Service Model Diagram

SaaS
Software
PaaS
Platform
IaaS
Infrastructure
Infrastructure
Provider Managed
Click on any layer to see what you manage vs what the provider manages
Model User Manages Provider Manages Example
IaaS
Infrastructure as a Service		 OS, runtime, applications, data Physical servers, storage, networking Virtual Machines
PaaS
Platform as a Service		 Application code and data OS, middleware, runtime, servers App Hosting
SaaS
Software as a Service		 User access and configuration Entire stack (infrastructure to application) Email/CRM

Service Model Configurator

Configure Your Cloud Setup

Choose your requirements and see which service model fits best. This helps you understand the practical decision-making process.

Recommended Service Model:
IaaS
You need full control over the operating system and runtime environment. IaaS gives you maximum flexibility.

Trade-off Principle: As you move toward SaaS, convenience increases, but your control and customization options decrease. Choose based on required control and team expertise.

Hands-On Lab: Infrastructure as Code

Learn by doing. Write your first cloud configuration using real Infrastructure as Code tools.

Terraform AWS Lab

Create an S3 Bucket using Terraform

Follow these steps to create your first cloud resource:

  1. Edit the Terraform configuration below to customize your bucket name
  2. Click "Run Configuration" to validate your code
  3. Check the output to see what would be created
main.tf
# Welcome to the Terraform Lab! # # Edit the bucket name in the code above and click # "Run Configuration" to see what would be created. # # This simulates real Terraform execution without # needing AWS credentials.

Real AWS Challenge

Ready for the real thing? Here's how to try this with actual AWS:

  1. Create an AWS Free Tier account
  2. Install Terraform on your computer
  3. Create a new file with the code above
  4. Run terraform init then terraform plan
  5. If everything looks good, run terraform apply

Security: Shared Responsibility

Understanding the division of security responsibilities between cloud providers and customers.

IAM Policy Simulator

Practice Creating Secure IAM Policies

Learn how to create least-privilege security policies by configuring access controls below.

Hold Ctrl to select multiple services
Generated IAM Policy: 
{
  "Version": "2025-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "s3:GetObject",
        "s3:ListBucket"
      ],
      "Resource": "*"
    }
  ]
}

Security of the Cloud

The cloud provider secures the underlying infrastructure:

  • Physical data centers
  • Core network infrastructure
  • Host OS and hypervisors

Security in the Cloud

The customer is responsible for everything they deploy or configure:

  • Data protection (encryption)
  • Identity and Access Management (IAM)
  • Correct configuration management

Critical Note: Most cloud breaches stem from customer configuration errors ("Security in the Cloud"), not platform vulnerabilities.

Cloud Challenge Quiz

Test your knowledge! Click on each question to reveal the answer and get detailed feedback.

What is the financial model of the cloud called?

Answer: Operational Expenditure (OpEx).

Who is responsible for securing uploaded data?

Answer: The Customer.

Which service model gives the most OS control?

Answer: Infrastructure as a Service (IaaS).

What is defining infrastructure with code called?

Answer: Infrastructure as Code (IaC).