Networks Grade 10
A computer network connects two or more devices so they can communicate and share resources. Networks are what make the internet, school computer labs, and your home Wi-Fi possible.
Why Would You Connect Computers Together?
Imagine your school has 30 computers but only 2 printers. Without a network, only the computers physically connected to a printer could print. With a network, every computer can send print jobs to either printer — that's sharing resources.
Networks make all of the following possible:
- Resource sharing — share printers, scanners, internet connections, and storage across multiple computers
- File sharing — send a document from one computer to another without a USB drive
- Communication — email, instant messaging, video calls (e.g. your school uses Microsoft Teams or Google Meet)
- Centralised data and backups — store all student data on one server so it's accessible from any computer in the lab
- Internet access — one router can give all devices in a building internet access
- Remote work — teachers can access school systems from home via a VPN (Virtual Private Network)
Your school's computer lab is a LAN (Local Area Network). Every computer connects through a switch to a router, which connects to your ISP (Internet Service Provider) — maybe Telkom, MWEB, or Vodacom. That router gives every computer in the lab access to the internet.
Network Size Classifications
| Type | Full name | Coverage area | Typical speed | SA Examples |
|---|---|---|---|---|
| PAN | Personal Area Network | ~1–3 metres (arm's reach) | Low–medium | Bluetooth headphones, Apple Watch connected to phone, wireless keyboard |
| HAN | Home Area Network | Within one household | Medium–fast | Home Wi-Fi router (Telkom/Vodacom fibre), smart TV, gaming console, laptop all connected |
| LAN | Local Area Network | One building or campus | Fast (100 Mbps–10 Gbps) | School computer lab, office building network, university campus network |
| WAN | Wide Area Network | Cities, countries, continents | Varies widely | The Internet; MTN/Vodacom cellular network connecting towns across SA |
Network Topologies — Star Topology
A topology describes the physical layout of how devices are connected in a network. The most common topology used in school labs and offices is the Star Topology: every device connects directly to a central switch or hub.
Star Topology — Advantages and Disadvantages
| Advantages | Disadvantages |
|---|---|
| Easy to add new devices — just connect to the switch | If the central switch fails, the whole network goes down |
| One faulty cable only affects that one device | Requires more cable than some other topologies |
| Easy to diagnose faults — test one connection at a time | Cost of the switch adds to setup expense |
| Most widely used in schools and offices | Performance depends on the quality of the switch |
Essential Network Components
Data from your computer travels through several devices before it reaches the internet. Here is how they connect:
Network Hardware Reference
| Component | Purpose | SA Example |
|---|---|---|
| NIC (Network Interface Card) | Connects a device to a network. Every computer has one, either built-in or as an add-on card. Assigns the device a unique MAC address. | Your laptop's built-in Ethernet port or Wi-Fi card |
| Switch | Connects multiple devices within a LAN. Smarter than a hub — sends data only to the specific device it's addressed to (using MAC addresses). | The network switch in your school's server room connecting all computers in the lab |
| Router | Connects two or more networks together. Routes data between your LAN and the internet using IP addresses. Usually also acts as a firewall. | The Telkom/Vodacom router in your home or school that gives Wi-Fi access |
| Modem | Converts digital computer data into a signal suitable for your internet line (ADSL, fibre, LTE), and vice versa. "Modulator-Demodulator". | Telkom ADSL modem, or LTE modem (like a Huawei Wifi router) |
| Access Point (Wi-Fi) | Extends wireless network coverage. Connects wirelessly to clients and wired to the switch/router. | Extra Wi-Fi routers placed in different classrooms of a large school |
Network Types — Client-Server vs Peer-to-Peer
Client-Server Network
A central server provides services (files, printers, internet access, authentication) to multiple client computers. The server is a dedicated, powerful computer that is always on.
Peer-to-Peer (P2P) Network
All computers have equal status — any device can be both client and server. No single central machine is in charge. Common in small home networks.
| Feature | Client-Server | Peer-to-Peer (P2P) |
|---|---|---|
| Cost | Expensive — dedicated server hardware needed | Cheap — any computer can participate |
| Security | Strong — administrator controls all access | Weak — each device manages its own security |
| Management | Centralised — easy to manage by one admin | Decentralised — hard to manage as network grows |
| Performance | Consistent — server is optimised for the job | Variable — depends on each computer's specs |
| Backups | Easy — all data is on the server | Difficult — data is spread across all machines |
| Failure point | If server fails, whole network is affected | One computer failing rarely affects others |
| Best for | Schools, businesses, organisations (10+ users) | Small home networks (2–5 devices) |
| SA Example | School lab with a Windows Server; bank branch | Two friends sharing files between laptops at home |
Communication Media
The medium is the physical pathway over which data travels. Choosing the right medium depends on the required speed, distance, security, and budget.
| Medium | How it works | Speed | Range | Security | Cost | SA Example |
|---|---|---|---|---|---|---|
| UTP Cable (Ethernet, Cat5e/Cat6) |
Electrical signals through 4 twisted copper pairs. RJ45 connectors. | 100 Mbps – 10 Gbps | Up to 100 m per segment | Good — hard to intercept without physical access | Low — cheapest option | School computer lab wiring; office desk connections |
| Fibre Optic | Light pulses through thin glass/plastic strands. Not affected by electrical interference. | 1 Gbps – 100+ Gbps | Kilometres (single-mode) | Very high — almost impossible to tap | Higher — more expensive to install | Openserve/Vumatel fibre to your home; undersea cables connecting SA to Europe |
| Wi-Fi (802.11 radio waves) |
Radio signals transmitted through air. No cable needed. | 54 Mbps – 9.6 Gbps (Wi-Fi 6) | 10–100 m indoors | Needs encryption (WPA3) — radio signals can be intercepted | Low — just a router; no cabling needed | Home routers; school library hotspots; coffee shops |
| LTE / 5G (mobile broadband) |
Radio signals through cell towers. Cellular network. | 10–100+ Mbps (LTE); up to 1 Gbps (5G) | Kilometres per tower | Moderate — carrier-managed encryption | Variable — data bundle costs | MTN, Vodacom, Cell C towers connecting rural SA; mobile data on phones |
| Infrared | Infrared light — requires line of sight, no obstacles. | Very slow | Very short (<1 m) | Line of sight only | Very low | TV remotes, old phone data transfers (largely obsolete) |
Many South African schools and homes are getting fibre connections through providers like Openserve (Telkom), Vumatel, and Frogfoot. Before fibre, most homes used ADSL over copper phone lines. In rural areas where fibre hasn't reached, LTE (4G) from MTN, Vodacom, or Rain is the main option for internet access.