Network Components and Social Media
Senior 2 · ICT
Network Components and Social Media
Lesson 1 of 4
20 min
Picture the computer lab at a secondary school in Huye. Thirty students are working at the same time, but there is only one printer in the corner and one internet line coming into the school. Every student can still print and go online. That works because the computers are joined into a network.
Networks sit behind much of daily life in Rwanda. When a parent pays school fees with MTN MoMo, when you apply for a document on Irembo, or when a hospital orders blood from a Zipline centre, devices are exchanging data across networks. In this lesson you will learn which devices join a network and what they share.
The lab in Huye contains:
The computers, the laptop and the printer create and use data. The switch and the router only pass data along. Together they form one network.
A computer network is two or more computing devices linked together so that they can exchange data and share resources. The link can be a cable or a wireless signal.
Any device connected to a network is a node. A node that sends or receives data for its own use, such as a computer or a phone, is called a host or end device. A node whose job is to pass data along, such as a switch or a router, is a network device. You will study network devices in Lesson 3.
| End device | What it does on the network |
|---|---|
| Desktop computer or laptop | Sends and receives files, email and web pages |
| Smartphone or tablet | Browses, messages, pays with mobile money |
| Network printer | Prints documents sent from many computers |
| Server | A powerful computer that provides a service to other devices, such as storing files or running a website |
| IP camera (CCTV) | Sends live video to a screen or recorder |
| Smart TV | Streams video from the internet |
| Point-of-sale (POS) card machine | Sends payment details to a bank |
To join a network, a device needs a network interface card (NIC): the part that connects it to the network. A wired NIC has a socket for a network cable; a wireless NIC uses a small antenna. Every NIC carries its own permanent hardware address, called a MAC address, so that data can be delivered to the right device.
A server provides a service; a client requests it. When you open Irembo on a phone, the phone is the client, and Irembo's computers are the servers that hold the forms and process your application.
A network resource is anything that the devices on a network can share:
A school has 30 computers and a printer costs 250,000 Frw.
| Advantages | Disadvantages |
|---|---|
| Hardware, files and the internet line are shared, which saves money | Cables, network devices and installation cost money |
| Users communicate quickly by email and messaging | A virus can spread from one computer to all the others |
| Files can be stored and backed up in one central place | If the server or the switch fails, many users are affected at once |
| Software can be installed and updated centrally | Shared data must be protected from people who should not see it |
Tip
Exam tip: a device is something that is connected; a resource is something that is shared. If a question asks for "network resources", do not answer "cables" or "a switch": those carry data but are not shared. A printer can be both. It is a device, and once it is shared it is also a resource.
Sort these into end devices and network resources: a laptop, a shared "S2 Notes" folder, a smartphone, the school's internet connection, an IP camera.
Solution: End devices: the laptop, the smartphone and the IP camera. Resources: the shared folder and the internet connection. Each device is connected; each resource is shared.
A school has 40 computers and a printer costs 300,000 Frw. It buys 2 network printers instead of one per computer. How much does it save?
Solution: One per computer: 40 × 300,000 = 12,000,000 Frw. Two shared printers: 2 × 300,000 = 600,000 Frw. Saving: 12,000,000 − 600,000 = 11,400,000 Frw.
Mugisha buys electricity tokens with MoMo on his phone. Which is the client and which is the server?
Solution: His phone is the client because it requests the payment. The mobile-money provider's computers are the servers because they process the payment and send back the token.
Give two disadvantages of connecting all the computers in a lab to one network.
Solution: Any two of: a virus can spread to every computer; if the switch or server fails, everyone loses access; the equipment and installation cost money; shared files must be protected with passwords and permissions.
Summary
Sources and credits
The worked examples and practice items were written by Ganzaa.
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
