CAIE 9618 · Paper 1 · Topic 1.2.9

Cloud Computing & IoT

IaaS · PaaS · SaaS · Internet of Things · Benefits & Concerns

CSZone Cambridge International AS & A Level Computer Science 9618

Cloud Computing

Using IT Resources Over the Internet

Cloud computing means accessing computing resources (servers, storage, software, databases) via the internet rather than owning or managing local hardware. Resources are provided on demand by a third party.

IaaS

Infrastructure

Virtual machines, storage, networking. User manages OS and above. e.g. AWS EC2, Azure VMs

PaaS

Platform

Development environment + runtime. Provider manages OS. e.g. Google App Engine, Heroku

SaaS

Software

Ready-to-use applications. User manages data only. e.g. Gmail, Google Docs, Office 365

Benefits of Cloud Computing

Why Organisations Use the Cloud

Scalability — easily increase or decrease resources on demand

Cost reduction — no upfront hardware costs; pay-as-you-go model

Accessibility — access data/apps from any device with internet connection

Automatic updates — provider maintains and updates software/hardware

Disaster recovery — data replicated across multiple data centres

Collaboration — multiple users can work on same files simultaneously

No maintenance burden — hardware managed by provider

Concerns with Cloud Computing

Risks and Limitations

SECURITY & PRIVACY

Data stored on third-party servers — provider could access data

If provider is breached, customer data is at risk

Compliance concerns — data may be stored in different countries

RELIABILITY

Dependent on internet connection — no connectivity = no access

Provider downtime affects all users

Vendor lock-in — difficult to switch providers

Internet of Things (IoT)

Connected Everyday Devices

The Internet of Things (IoT) refers to everyday physical devices embedded with sensors, software, and connectivity, allowing them to collect and exchange data over the internet — without human intervention.

Examples: smart thermostats, fitness trackers, connected fridges, CCTV cameras, smart meters, industrial sensors

Benefits: automation, remote monitoring, energy efficiency, real-time data collection

Security risks: many IoT devices have weak/default passwords — easy targets for attackers

Privacy: constant data collection raises concerns about surveillance and data ownership

Exam Practice

Cambridge-style questions

Question 1

Describe the difference between IaaS, PaaS, and SaaS. Give one example of each.

6 marks

2 marks

IaaS: provides virtual hardware (servers, storage, networking) — user manages OS and software. e.g. AWS EC2, Azure Virtual Machines

2 marks

PaaS: provides a development platform and runtime environment — user manages application code only. e.g. Google App Engine, Heroku

2 marks

SaaS: provides fully managed applications — user only manages data. e.g. Google Docs, Gmail, Microsoft 365

Common Mistakes

Don't lose easy marks

1

Saying cloud computing is free — it's typically pay-as-you-go or subscription-based. While it can reduce capital costs, organisations still pay operational costs to providers.

2

Confusing IaaS and SaaS — IaaS is raw infrastructure (like renting a server), SaaS is a complete application (like using Gmail). Don't say "IaaS = using software online."

3

Saying IoT requires human input — IoT devices communicate autonomously with other devices or the internet without human intervention. That's the defining characteristic of IoT.

Topic Summary — 1.2.9

What You Need to Know

CLOUD SERVICE MODELS

IaaS: infrastructure (VMs, storage) — AWS/Azure
PaaS: platform + runtime — Heroku/App Engine
SaaS: full software — Gmail/Office 365
Key: how much does the user manage?

CLOUD BENEFITS

Scalable, no hardware costs, accessible anywhere
Auto-updates, disaster recovery, collaboration
Pay-as-you-go / subscription pricing

CLOUD CONCERNS

Security: data on third-party servers
Privacy: provider could access data
Reliability: needs internet connection
Vendor lock-in risk

IoT

Physical devices connected to internet
Autonomous data exchange — no human needed
Smart home, wearables, industrial sensors
Risks: weak security, privacy concerns

CSZone

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