Beginner Guide · Cloud Computing Fundamentals
What Are the Basics of Cloud Computing You Must Know
Quick summary — cloud computing basics you must know
Cloud computing is renting computing resources over the internet instead of owning them. Every beginner should know six core concepts: service models (IaaS, PaaS, SaaS), deployment types (public, private, hybrid), virtualization, scaling and elasticity, the major providers (AWS, Azure, GCP), and the shared responsibility model. Master these and you can start working with real cloud services.
Here's what this guide covers:
- What cloud computing actually is — in plain language.
- The three service models — IaaS, PaaS, SaaS.
- Deployment types — public, private, hybrid, multi-cloud.
- Core concepts — virtualization, scaling, elasticity.
- The major providers — AWS, Azure, GCP.
- The shared responsibility model — who secures what.
- An 8-week roadmap to get hands-on.
SECTION 01What is cloud computing?
Cloud computing is the delivery of computing services — servers, storage, databases, networking, software — over the internet. You rent what you need, when you need it, instead of buying and maintaining physical hardware.
| Traditional (on-premise) | Cloud computing |
|---|---|
| Buy and install servers | Rent servers by the hour |
| Months to provision | Minutes to provision |
| Pay upfront for capacity | Pay only for what you use |
| You handle all maintenance | Provider handles hardware |
| Hard to scale quickly | Scale in minutes |
| Fixed cost, predictable | Variable cost, flexible |
SECTION 02Service models — IaaS, PaaS, SaaS
Cloud services come in three main models. The difference is how much you manage versus how much the provider manages.
| Model | What you get | You manage | Provider manages | Examples |
|---|---|---|---|---|
| IaaS | Virtual machines, storage, networking | OS, runtime, apps, data | Hardware, virtualization | AWS EC2, Azure VMs |
| PaaS | Platform to deploy apps | Apps, data | OS, runtime, hardware | Heroku, App Service |
| SaaS | Ready-to-use software | Just your data and settings | Everything else | Gmail, Slack, Salesforce |
# IaaS — rent a virtual machine
# (AWS CLI example)
aws ec2 run-instances \
--image-id ami-0abcdef1234567890 \
--instance-type t2.micro \
--key-name my-key \
--security-group-ids sg-12345678
# You get a raw VM.
# You install the OS updates, runtime,
# and everything on top.# PaaS — push code, platform handles runtime
# (Heroku example)
git push heroku main
# Platform installs dependencies,
# builds the app, runs it, manages
# scaling and OS patching.
# You only ship code.
# No server config, no OS updates.SECTION 03Deployment types
Where the cloud runs matters. Here are the four deployment models.
| Type | What it means | Best for |
|---|---|---|
| Public cloud | Shared infrastructure owned by a provider (AWS, Azure) | Most apps, startups, cost-sensitive workloads |
| Private cloud | Dedicated infrastructure for one organisation | Banks, healthcare, high-compliance industries |
| Hybrid cloud | Mix of public and private, connected together | Enterprises migrating gradually |
| Multi-cloud | Using multiple public providers (AWS + GCP) | Avoiding vendor lock-in, redundancy |
SECTION 04Core concepts — virtualization & scaling
These underlying concepts make cloud computing possible. Understanding them helps you make better decisions.
| Concept | What it means | Why it matters |
|---|---|---|
| Virtualization | Running multiple virtual machines on one physical server | Enables efficient resource use and isolation |
| Vertical scaling | Making a single server bigger (more CPU/RAM) | Simple, but limited by hardware ceiling |
| Horizontal scaling | Adding more servers to share the load | Cloud-native approach — scales almost indefinitely |
| Elasticity | Automatically adding/removing resources with demand | Saves cost — you only pay for what's used |
| Serverless | Running code without managing servers at all | Pay only per execution — great for spiky workloads |
| Containerization | Packaging apps into portable units (Docker) | Consistent across environments |
# Auto-scaling configuration (conceptual)
When CPU > 70% for 5 minutes:
→ Add 1 more server
When CPU < 30% for 10 minutes:
→ Remove 1 server
Minimum servers: 2
Maximum servers: 10
This is elasticity:
- Handles traffic spikes automatically
- Reduces cost during quiet hours
- No human intervention needed# Serverless function (AWS Lambda example)
import json
def handler(event, context):
name = event.get("name", "world")
return {
"statusCode": 200,
"body": json.dumps(f"Hello, {name}!")
}
# You write the function.
# The cloud provider:
# - Runs it when triggered
# - Scales it automatically
# - Charges per execution
# No server management at all.SECTION 05Major providers & shared responsibility
Three providers dominate the market. Here's how they compare, plus the most important concept for cloud security.
| Provider | Strengths | Best for |
|---|---|---|
| AWS (Amazon) | Broadest service catalogue, largest market share | Most roles — safest first cloud to learn |
| Azure (Microsoft) | Strong enterprise + Windows integration | Corporate environments, Microsoft shops |
| GCP (Google) | Data analytics, ML, Kubernetes | Data-heavy and AI-heavy workloads |
| Shared responsibility | Provider | You |
|---|---|---|
| Physical security | ✓ | — |
| Hardware & network | ✓ | — |
| Hypervisor | ✓ | — |
| OS patching (IaaS) | — | ✓ |
| App configuration | — | ✓ |
| Identity & access | — | ✓ |
| Your data | — | ✓ |
SECTION 06Interview Q&A — cloud computing basics
Q1What's the difference between IaaS, PaaS, and SaaS?
The difference is how much you manage. IaaS: you manage the OS and above. PaaS: you manage only the app and data. SaaS: you manage only your data and settings. The provider handles everything below that line.
Q2Is cloud computing more expensive than on-premise?
It depends. For small or variable workloads, cloud is often cheaper because you only pay for what you use. For large, steady-state workloads, on-premise can be cheaper — but you lose flexibility. Cost is a design choice, not an inherent property.
Q3Which cloud provider should I learn first?
AWS. It has the largest market share, the broadest service catalogue, and the most learning resources. Once you know AWS, Azure and GCP are easier to pick up.
Q4Do I need to know Linux for cloud computing?
Yes, for most roles. Most cloud servers run Linux, and you'll use the terminal daily. Basic Linux skills (file operations, users, permissions, SSH) are essential — especially for IaaS.
Q5Is the cloud secure?
The cloud provider secures the physical and underlying infrastructure. You are responsible for configuring your resources securely — IAM, storage permissions, encryption, network rules. Most cloud breaches are customer-side misconfigurations, not provider failures.
SECTION 07Test yourself — cloud computing basics
Five questions. No sign-up.
0 / 5Pick an answer to see why it is right or wrong.
SECTION 08Frequently asked questions
What are the three main cloud service models?
IaaS (Infrastructure as a Service), PaaS (Platform as a Service), and SaaS (Software as a Service). They differ in how much the provider manages versus how much you manage.
What's the difference between public and private cloud?
Public cloud is shared infrastructure owned by a provider (AWS, Azure). Private cloud is dedicated infrastructure for one organisation. Most companies use public cloud first, then add private or hybrid for compliance.
What is virtualization in cloud computing?
Virtualization lets one physical server run multiple isolated virtual machines. It's the technology that makes cloud computing economically possible — you can rent a slice of a server rather than buying the whole thing.
What's the shared responsibility model?
The provider secures the physical infrastructure and hypervisor. You secure your OS, apps, IAM, and data. Most cloud breaches are caused by customer-side misconfigurations — not provider failures.
How long does it take to learn cloud computing basics?
With 2-3 hours daily, 6-8 weeks is realistic for the basics plus hands-on practice. Real job-readiness — especially for cloud engineer roles — takes 4-6 months of consistent work.
SECTION 09Related reads
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