Know and understand the characteristics, uses and issues relating to cloud computing

4. Networks and the Effects of Using Them

Types of Networks

• Local Area Network (LAN) – covers a small area like a school or office. Think of it as a neighbourhood where everyone shares a common playground. • Wide Area Network (WAN) – connects multiple LANs over large distances. It’s like a road network that lets cities talk to each other. • Wireless LAN (WLAN) – uses radio waves instead of cables. Imagine a magic carpet that lets devices hop from one spot to another. • Virtual Private Network (VPN) – creates a secure tunnel over the internet. Think of it as a secret passage that only you and your friends can use. • Internet of Things (IoT) Network – connects everyday objects. Picture a city of talking devices where your kettle, fridge, and smartwatch chat with each other.

Effects of Using Networks

• Instant communication – messages travel in milliseconds, like a bullet train between cities.
• Access to shared resources – files, printers, and applications are available to all users, similar to a community library.
• Increased collaboration – students can work together on projects from anywhere.
• Potential for security risks – data can be intercepted if not protected, like a leaky pipe that leaks secrets.
• Dependence on infrastructure – if the network goes down, everything stops, just like a traffic jam that halts a city.

Cloud Computing Overview

Cloud computing delivers computing services (storage, servers, databases, networking, software) over the internet. It’s like renting a super‑powerful computer that lives in a data centre far away, and you can use it whenever you need it.

Characteristics of Cloud Computing

Types of Cloud Models

1. Public Cloud – services offered over the public internet (e.g., Google Cloud, AWS). Think of it as a public park open to everyone.
2. Private Cloud – dedicated infrastructure for a single organisation. Like a private club with exclusive access.
3. Hybrid Cloud – combination of public and private clouds. Imagine a hybrid vehicle that switches between electric and petrol.
4. Community Cloud – shared by several organisations with common concerns. Like a co‑op community centre for neighbours with similar interests.

Uses of Cloud Computing

• Data storage and backup – keep files safe in the cloud, like a digital safe.
• Software as a Service (SaaS) – use applications online (e.g., Google Workspace). It’s like renting a toolbox that you can use from any device.
• Infrastructure as a Service (IaaS) – rent virtual machines. Think of it as building blocks you can assemble as needed.
• Platform as a Service (PaaS) – develop and deploy apps without managing servers. Like a playground where you can create games without worrying about the ground.
• Disaster recovery – quickly restore services after a failure. It’s like having a backup plan that kicks in automatically.

Issues Relating to Cloud Computing

1. Security and Privacy – data stored off‑site may be vulnerable. Think of it as leaving your diary in a public locker that others can access.
2. Data Sovereignty – laws vary by country, affecting where data can be stored. It’s like traveling with luggage that must follow different customs rules.
3. Reliability and Downtime – service outages can halt work. Imagine a power outage that stops all your games.
4. Vendor Lock‑In – moving data to another provider can be costly. It’s like being stuck in a long‑term lease you can’t break easily.
5. Cost Management – pay‑per‑use can become expensive if not monitored. Think of it as a water bill that spikes when you leave the tap running.
6. Bandwidth and Latency – slow internet can affect performance. It’s like a traffic jam that slows down your data.

Analogy: Cloud as a Library

• Books (Data) – stored in the cloud, ready to be borrowed. • Library Card (Account) – gives you access to the books. • Borrowing (Downloading) – you can read online or download for offline use. • Return (Deletion) – when you’re done, you can delete the data, freeing space for others. • Staff (Support) – helps you find the right resources and troubleshoot. This analogy helps students visualise how cloud services work and why they’re useful.

Key Takeaway

Cloud computing offers flexible, scalable, and cost‑effective solutions, but it also brings challenges such as security, privacy, and cost control. Understanding these characteristics helps you make informed decisions when using or designing networked systems.