Chapter 1 · Computer Networks

1.4Networking Devices

The five devices that build a network: NIC, switch, router, modem and wireless access point, and the job of each one.

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Full Stack Developer · AI Engineer · Reviewed 21 Oct 2026 · 3 min read

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A network is more than cables and computers. Special devices sit in between and move the data. Each one has its own job. This topic meets the five devices the book names, one by one.

Network Interface Card (NIC)

A device needs a NIC before it can join any network. Without one, it cannot talk to other devices at all.

A NIC can use a cable (wired) or radio waves (wireless). It both sends and receives data. Every NIC also carries its own unique address, called the MAC address. Today most devices have a NIC built in, so you rarely see it. Figure 1.6 in the book, "Network Interface Card", shows a card with an "Ethernet Port" where the cable plugs in.

Switch

A switch joins many devices into one network. When data arrives, it does not send it to everyone. It sends it only to the device it is meant for. This makes the network faster and more efficient. That is why switches are common in modern networks.

Router

A switch works inside one network. A router joins different networks to each other. It guides each data packet to its correct destination, using IP addresses. Routers connect our home and office networks to the Internet. They also add security and control.

Modem

The modem is the link between your local network and your Internet Service Provider (ISP), the company that sells Internet access. Its main job is conversion. Going out, it turns digital data into signals that can travel over the line. Coming in, it turns those signals back into digital form. Modems work with cable, DSL or fiber connections, and they often work together with a router.

In the book's class activity, the instructor explains the modem with a signal conversion example, and students then summarize it.

Wireless access point

A wireless access point gives Wi-Fi to phones, laptops and other wireless devices. It spreads the wireless network over a bigger area. Large buildings and campuses use many access points. They make the signal stronger and more stable. Figure 1.7 in the book, "Wireless Access Point", shows one access point sending Wi-Fi to a phone, a laptop and a desktop computer.

Device	Its job in one line
Network Interface Card (NIC)	lets a device connect to a network
Switch	sends data to the correct device
Router	connects different networks
Modem	connects the local network to the ISP and converts signals
Wireless access point	provides Wi-Fi connectivity

Practice this topic

All MCQs of this chapter with answers

Short questions

1.What is the function of a router?2 marks
Answer
From the book: "A router connects different networks together. It directs data packets to their correct destination. Routers connect local networks to the Internet. They use IP addresses to send data."
2.What are networking devices?2 marks
Answer
From the book: "Networking devices are used to connect computers and other devices in a network. These devices control the flow of data. Each device has a specific role in communication." The book's Summary (p.17): "Networking devices are hardware components, such as switches, routers, modems, NICs, and access points, used to connect devices and manage communication."
3.What is a Network Interface Card (NIC)?2 marks
Answer
From the book: "A Network Interface Card allows a device to connect to a network." "It can be wired or wireless. Each NIC has a unique address called MAC address. The NIC sends and receives data from the network."
4.What does a switch do?2 marks
Answer
From the book: "A switch connects devices and sends data to the correct device. Switches improve network speed and efficiency. Switches are common in modern networks."
5.What is a modem? Which two conversions does it perform?3 marks
Answer
From the book: "A modem connects a local network to an Internet Service Provider (ISP). It converts digital data into signals suitable for transmission. It also converts incoming signals back into digital form."
6.What is the role of a wireless access point?2 marks
Answer
From the book: "A wireless access point provides Wi-Fi connectivity. It allows wireless devices to connect to a network." "It extends wireless network coverage." "They improve signal strength and stability."

Long questions

1.Describe the main networking devices used in a computer network and explain their functions.8 marks
Answer
Open with the book's first lines: "Networking devices are used to connect computers and other devices in a network. These devices control the flow of data. Each device has a specific role in communication." Then cover all five sub-headings, using the book's text:
1. Network Interface Card (NIC): "A Network Interface Card allows a device to connect to a network (as shown in Figure 1.6). It can be wired or wireless. Each NIC has a unique address called MAC address. The NIC sends and receives data from the network. Without a NIC, a device cannot communicate on a network. NICs are built into most modern devices."
2. Switch: "A switch connects devices and sends data to the correct device. Switches improve network speed and efficiency. Switches are common in modern networks."
3. Router: "A router connects different networks together. It directs data packets to their correct destination. Routers connect local networks to the Internet. They use IP addresses to send data. Routers improve network security and control. Home and office networks use routers widely."
4. Modem: "A modem connects a local network to an Internet Service Provider (ISP). It converts digital data into signals suitable for transmission. It also converts incoming signals back into digital form. Modems are used with cable, DSL, or fiber connections. Internet access depends on a modem. Modems often work with routers."
5. Wireless access point: "A wireless access point provides Wi-Fi connectivity. It allows wireless devices to connect to a network (as shown in Figure 1.7). It extends wireless network coverage. Access points are used in large buildings and campuses. They improve signal strength and stability. Wireless access points support mobile connectivity."
A labelled sketch of Figure 1.6 (Network Interface Card, with the Ethernet Port) or Figure 1.7 (Wireless Access Point) can support the answer. The Summary (p.17) gives a one-line definition to open with: "Networking devices are hardware components, such as switches, routers, modems, NICs, and access points, used to connect devices and manage communication."

Aim for 250-350 words.
2.Explain the router and the modem. How is the job of each device different, and how do they work together?6 marks
Answer
Cover both sub-headings, using the book's text:
1. Router: "A router connects different networks together. It directs data packets to their correct destination. Routers connect local networks to the Internet. They use IP addresses to send data. Routers improve network security and control. Home and office networks use routers widely."
2. Modem: "A modem connects a local network to an Internet Service Provider (ISP). It converts digital data into signals suitable for transmission. It also converts incoming signals back into digital form. Modems are used with cable, DSL, or fiber connections. Internet access depends on a modem."
3. The difference, from the two texts: the router connects networks and directs data packets using IP addresses; the modem connects the local network to the ISP and converts digital data into signals and back.
4. Working together: "Modems often work with routers."
Aim for 150-250 words.

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