Know and understand how data is stored, managed and shared using cloud computing

Networks and Cloud Computing

Objective

Understand how data is stored, managed and shared using cloud computing, how networks enable these services, and the effects – both positive and negative – of using networks and IT on individuals and society.

1. Computer System Fundamentals (IGCSE 0417 1‑5)

  • Central Processing Unit (CPU) – the “brain” that executes instructions.
  • Memory

    • RAM (Random‑Access Memory) – volatile, short‑term storage used while programs run.
    • ROM (Read‑Only Memory) – non‑volatile, stores firmware such as the BIOS.

  • Internal (primary) storage vs. backing (secondary) storage

    • Primary: RAM, cache – fast, temporary.
    • Secondary: Hard‑disk drives (HDD), solid‑state drives (SSD), optical media, magnetic tape – persistent.

  • Operating Systems (OS)

    • Desktop/Server OS – Windows, macOS, Linux.
    • Mobile OS – Android, iOS.
    • GUI (graphical) vs. CLI (command‑line) interfaces.

  • Device categories

    • Desktop computers – fixed, high‑performance.
    • Laptops & tablets – portable, integrated components.
    • Emerging technologies – AI‑enabled assistants, XR (AR/VR) headsets, IoT wearables.

2. Micro‑processor‑Controlled Devices (Syllabus 5.1)

Devices that contain a small CPU and run specialised software. Examples:

  • Smart home hubs (e.g., Amazon Echo, Google Nest)
  • Autonomous vehicles and drones
  • Wearable health monitors (smart watches, fitness bands)
  • Industrial sensors and PLCs (Programmable Logic Controllers)

3. What Is Cloud Computing?

Delivery of computing services – servers, storage, databases, networking, software, analytics and intelligence – over the Internet (“the cloud”). Services are accessed on a pay‑as‑you‑go basis, so users do not need to own or maintain the underlying hardware.

4. Cloud Service Models (Service Models)

Service ModelWhat It ProvidesTypical Users
Infrastructure as a Service (IaaS)Virtualised hardware – compute, storage, networking.Businesses that need control over OS and applications.
Platform as a Service (PaaS)Development platforms, databases, middleware.Developers building, testing and deploying apps.
Software as a Service (SaaS)Fully functional applications delivered via a web browser.End‑users needing ready‑to‑use software (e‑mail, office suites).

5. Network Hardware

  • Network Interface Card (NIC) – connects a device to a network.
  • Router – forwards data between different networks (e.g., LAN to the Internet).
  • Switch – connects multiple devices within the same network; uses MAC addresses to direct traffic.
  • Hub – repeats incoming signals to all ports (largely replaced by switches).
  • Bridge – links two network segments at the data‑link layer.
  • Wireless Access Point (WAP) – provides Wi‑Fi connectivity.
  • Bluetooth adapter – short‑range wireless link for personal area networks.
  • Modem – converts digital data to analogue signals for transmission over telephone or cable lines.

6. Common Network Topologies

TopologyKey FeaturesTypical Use
StarAll devices connect to a central switch or hub.Most modern LANs.
BusAll devices share a single communication line.Older Ethernet installations.
RingData travels in one direction around a closed loop.Token Ring networks (rare today).
MeshMultiple redundant paths between devices.Wireless back‑haul, critical infrastructure.

7. Types of Networks (Scope)

Network TypeScopeTypical Example
Personal Area Network (PAN)Centimetres‑to‑metresBluetooth headset, smartphone‑to‑laptop sync.
Local Area Network (LAN)Single building or campusSchool computer lab, office network.
Wireless LAN (WLAN)LAN using Wi‑FiHome Wi‑Fi router.
Metropolitan Area Network (MAN)City‑wideMunicipal broadband, university campus network.
Wide Area Network (WAN)Country or globalInternet, corporate branch‑office links.
IntranetPrivate network inside an organisationCompany internal portal.
ExtranetControlled access for external partnersSupplier portal.
InternetGlobal public networkWorld‑wide web, email.

8. Core Network Protocols

ProtocolOSI LayerPurpose
TCP (Transmission Control Protocol)TransportReliable, ordered delivery of data.
IP (Internet Protocol)NetworkAddressing and routing of packets.
HTTP / HTTPSApplicationWeb page request/response; HTTPS adds encryption.
FTP / SFTPApplicationFile transfer (SFTP is secure).
SMTPApplicationSending e‑mail.
DNSApplicationTranslates domain names to IP addresses.
DHCPApplicationAutomatically assigns IP addresses to devices.

9. How Data Is Stored in the Cloud

  • Data resides on remote servers housed in data centres.
  • Redundancy: Multiple copies stored on separate physical devices.
  • Scalability: Storage capacity can be increased instantly to match demand.
  • Virtualisation: Physical hardware is abstracted, presenting logical storage to users.
  • Geographically dispersed replication supports disaster recovery and low‑latency access.

10. Managing Data in the Cloud

  1. Provisioning – allocate storage or compute resources via a web console or API.
  2. Backup & Recovery – automated snapshots, versioning, point‑in‑time restores.
  3. Access Controls – role‑based permissions, multi‑factor authentication (MFA), least‑privilege principle.
  4. Monitoring & Optimisation – dashboards, usage alerts, cost‑analysis tools.
  5. Data Lifecycle Management – policies to archive or delete data when no longer needed.

11. Sharing and Collaboration

Centralised storage enables simultaneous work on the same files.

  • File‑sharing platforms – Google Drive, OneDrive, Dropbox (real‑time editing, version history).
  • Collaboration suites – Microsoft Teams, Slack, Zoom (chat, video, screen‑share, integrated document storage).
  • Permissions can be set at file, folder or organisational level (view, comment, edit, owner).

12. Effects of Using Networks for Cloud Services

Positive Effects

  • Accessibility: Access data from any Internet‑connected device.
  • Cost Efficiency: Reduces capital expenditure on on‑site hardware.
  • Scalability: Resources can be expanded or reduced quickly.
  • Collaboration: Supports teamwork across locations and time zones.
  • Reliability: Redundant data‑centres minimise downtime.

Negative Effects

  • Dependence on Internet: Services are unavailable during connectivity loss.
  • Latency: Large files or real‑time apps may suffer delays.
  • Security Risks: Data travels over networks and is stored off‑site.
  • Compliance Issues: Data may reside in jurisdictions with different laws.
  • Bandwidth Costs: Heavy cloud usage can increase ISP charges.

13. Security Considerations (Network + Cloud)

  • Encryption – TLS/SSL for data in transit; AES‑256 for data at rest.
  • Authentication – strong passwords, MFA, biometric options where available.
  • Firewalls & Intrusion Detection Systems – protect inbound/outbound traffic and monitor anomalies.
  • Anti‑malware/Anti‑virus – regular scans on client devices and, where offered, on cloud VMs.
  • Secure Email & Video Conferencing – use encrypted channels; avoid sharing sensitive data on public links.
  • E‑safety Practices – recognise phishing, avoid suspicious downloads, keep software up‑to‑date.
  • Regular Audits & Patch Management – review permissions, apply security patches promptly.
  • Backup Strategy – include offline or geographically separate copies to guard against ransomware.

14. Legal, Ethical and Environmental Issues

  1. Data‑protection legislation (GDPR, Data Protection Act) – rights of data subjects, consent, breach reporting.
  2. Intellectual‑property rights – respect copyright when storing or sharing content.
  3. Provider terms of service – understand who owns the data and how it may be used.
  4. Environmental impact – energy consumption of large data centres; importance of sustainable cloud practices.

15. Health & Wellbeing Effects of Using IT (ICT 0417 5)

  • Physical health

    • Repetitive‑strain injury (RSI) from prolonged typing or mouse use.
    • Eye strain and headaches caused by screen glare and blue‑light exposure.
    • Poor posture leading to back and neck problems.
    • Hearing damage from prolonged use of headphones at high volume.

  • Digital wellbeing

    • Information overload and reduced concentration.
    • Risk of addiction to social media, gaming or constant connectivity.
    • Break strategies – e.g., the 20‑20‑20 rule (every 20 min look at something 20 ft away for 20 sec).

  • Societal impact

    • Improved access to education and health services via e‑learning and tele‑medicine.
    • Greater cross‑cultural collaboration, but also the digital divide for those without reliable Internet.
    • Environmental considerations – energy use of data centres and e‑waste.

16. ICT Applications and the Systems Life‑Cycle (IGCSE 0417 6‑7)

Cloud services are integral to the five stages of the systems life‑cycle:

  1. Analysis – stakeholder needs are gathered using online surveys and collaborative tools.
  2. Design – prototypes are hosted on cloud platforms (e.g., Figma, Adobe XD) for rapid feedback.
  3. Development – code is written on cloud‑based IDEs (GitHub Codespaces, AWS Cloud9) and stored in version‑control repositories.
  4. Implementation – the finished system is deployed on IaaS/PaaS platforms; users access it via the Internet.
  5. Evaluation & Maintenance – usage analytics, remote monitoring and automated updates are delivered from the cloud.

Examples of ICT applications that rely heavily on cloud computing include:

  • Customer Relationship Management (CRM) – Salesforce, Zoho.
  • Learning Management Systems (LMS) – Moodle Cloud, Google Classroom.
  • Business intelligence dashboards – Power BI, Tableau Online.

17. Choosing a Cloud Provider – Key Criteria

CriterionWhy It MattersTypical Evaluation Question
Reliability (Uptime)Ensures continuous access to data.What is the provider’s SLA for uptime?
Security FeaturesProtects data from unauthorised access.Does the service offer encryption, MFA and firewalls?
Compliance SupportHelps meet legal requirements.Is the provider certified for GDPR, ISO 27001, etc.?
Cost StructurePrevents unexpected expenses.Are charges based on usage, storage, or flat fees?
ScalabilityAllows growth without major re‑configuration.Can resources be increased automatically?
Support & DocumentationHelps resolve issues quickly.Is 24/7 technical support available?

18. Summary

Cloud computing depends on robust network infrastructure to store, manage and share data efficiently. A solid grasp of computer system components, network hardware, topologies, protocols, and cloud service models—combined with awareness of benefits, risks, security measures, legal/ethical issues, health implications and the systems life‑cycle—enables students to make informed, responsible decisions about using cloud services in personal, educational and business contexts.

Suggested diagram: Flow of data – User device → Internet (router/Wi‑Fi) → Cloud data centre (servers, storage, processing) → Returned results or shared with collaborators.