What is cloud storage?

Cloud storage is a service where data is stored on remote servers
owned and managed by a third-party provider, accessed over the internet.

Cloud Storage = Storing data on remote servers accessed via the internet,
rather than on a local physical device.

The word "cloud" refers to the internet and the remote infrastructure behind it.

The user does not own or manage the physical hardware storing their data.

Data can be accessed from any device with an internet connection.

Examples: Google Drive, OneDrive, Dropbox, iCloud, Amazon S3.

2. How Cloud Storage Works

Cloud providers store data across multiple servers in different locations.

Data is replicated (copied) across several servers — if one fails,
the data is safe on another.

This is called redundancy — ensuring data is never lost due to a
single hardware failure.

3. Examples of Cloud Storage Services

Service	Provider	Typical Use
Google Drive	Google	Documents, photos, collaboration
OneDrive	Microsoft	Windows integration, Office files
iCloud	Apple	iPhone/Mac backups and files
Dropbox	Dropbox Inc.	File sharing and team collaboration
Amazon S3	Amazon	Business and developer storage

4. Cloud Storage vs Local Storage

Feature	Local Storage	Cloud Storage
Location	Physical device (HDD/SSD/USB)	Remote servers over internet
Internet needed?	❌ No	✅ Yes
Capacity	Fixed — limited by hardware	Scalable — increase as needed
Accessibility	Only from that device	Any device, anywhere
Cost	One-off hardware purchase	Ongoing subscription fee
Backup	User's responsibility	Handled by provider
Risk of loss	Fire, theft, physical damage	Provider failure, hacking
Sharing files	Physically transfer needed	Easy — share a link

5. Advantages of Cloud Storage

✅ Accessibility

Access files from any device (laptop, phone, tablet) anywhere in the world.

No need to carry a USB drive or external hard disk.

✅ Automatic Backup and Recovery

Cloud providers automatically back up data across multiple servers.

If your local device is lost, stolen, or broken, your data is still safe.

✅ Scalable Storage

Easily increase storage capacity by upgrading a subscription plan.

No need to buy new physical hardware.

Share a file with anyone using a link.

Multiple users can collaborate on the same document simultaneously.

✅ No Hardware Maintenance

The provider manages all server hardware, updates, and repairs.

The user has no maintenance responsibilities.

✅ Cost-Effective for Large Storage

No large upfront cost for hardware.

Pay only for what you use — subscription-based.

6. Disadvantages of Cloud Storage

❌ Requires Internet Connection

Without an internet connection, files cannot be accessed.

A slow connection means slow upload/download speeds.

❌ Ongoing Subscription Cost

Most cloud services charge a recurring monthly or annual fee.

Over time, this can exceed the cost of buying local storage.

❌ Security and Privacy Concerns

Data is stored on third-party servers — the user has less control.

Risk of data breaches, hacking, or unauthorised access.

The provider may be able to view your data in some circumstances.

❌ Dependency on the Provider

If the provider goes out of business or changes their service, access to
data may be lost.

The provider's terms and conditions govern how data is stored and used.

❌ Limited Control

Users cannot directly manage the physical hardware.

Data may be stored in a different country — raising legal jurisdiction issues.

7. Security in Cloud Storage

Cloud providers use several methods to keep stored data secure:

Security Measure	Description
Encryption	Data is encrypted during transfer (in transit) and while stored (at rest)
Authentication	Users must log in with a username and password
Two-Factor Authentication (2FA)	An extra verification step (e.g. code sent to phone)
Redundancy	Data copied across multiple servers/locations
Firewalls	Protect servers from unauthorised network access
Regular backups	Provider takes automatic backups of stored data

8. Cloud Storage and Collaboration

One of the biggest benefits of cloud storage is enabling real-time collaboration:

All users see changes immediately.

No need to email files back and forth.

Version history allows users to undo changes or restore earlier versions.

9. Typical Uses of Cloud Storage

Use Case	Example
Personal file backup	Backing up photos from a smartphone to iCloud
Document collaboration	A team editing a report together on Google Drive
Software delivery	Downloading apps and updates from the cloud
Streaming services	Netflix storing films on cloud servers
Business data storage	A company storing customer records on Amazon S3
Disaster recovery	Restoring a business's data after a system failure

10. Cloud Storage in the Context of Other Storage

Cloud storage sits beyond local secondary storage in the hierarchy —
it is the furthest from the CPU, slowest to access (dependent on
internet speed), but potentially unlimited in size.

11. Key Vocabulary

Term	Definition
Cloud Storage	Storing data on remote servers accessed via the internet
Remote Server	A computer in a data centre that stores data for many users
Data Centre	A large facility housing many servers owned by a cloud provider
Redundancy	Copying data across multiple servers to prevent loss
Encryption	Scrambling data so it cannot be read without the correct key
Scalable	Can be easily increased or decreased in size as needed
Subscription	A recurring payment for continued access to a service
Synchronisation	Keeping files updated and identical across multiple devices
Two-Factor Authentication	A login method requiring two forms of verification
Bandwidth	The amount of data that can be transferred over an internet connection per second

12. Exam Tips ✅

Always give specific named examples of cloud storage services
(e.g. Google Drive, iCloud, OneDrive) — not just "the cloud".

The two most important advantages to remember:
access from anywhere and automatic backup/redundancy.

The two most important disadvantages to remember:
requires internet and security/privacy concerns.

A very common exam question: "Give one advantage and one disadvantage
of storing data in the cloud compared to a local hard drive."
— Advantage: accessible from any device anywhere.
— Disadvantage: requires an internet connection / security concerns.

Know that cloud providers use encryption to protect data
both in transit and at rest — this is frequently tested.

Do not confuse cloud storage with RAM or virtual memory —
cloud storage is a form of permanent secondary storage, just
located remotely rather than inside the device.

Redundancy is a key feature — data is replicated so that
a single server failure does not result in data loss.

Cambridge (CIE) IGCSE Computer Science — 0478 / 0984

2. How Cloud Storage Works#

3. Examples of Cloud Storage Services#

4. Cloud Storage vs Local Storage#

5. Advantages of Cloud Storage#

✅ Accessibility#

✅ Automatic Backup and Recovery#

✅ Scalable Storage#

✅ Easy File Sharing and Collaboration#

✅ No Hardware Maintenance#

✅ Cost-Effective for Large Storage#

6. Disadvantages of Cloud Storage#

❌ Requires Internet Connection#

❌ Ongoing Subscription Cost#

❌ Security and Privacy Concerns#

❌ Dependency on the Provider#

❌ Limited Control#

7. Security in Cloud Storage#

8. Cloud Storage and Collaboration#

9. Typical Uses of Cloud Storage#

10. Cloud Storage in the Context of Other Storage#

11. Key Vocabulary#

12. Exam Tips ✅#