Comprehensive Notes Network Devices for Class 12

In this article, we will talk about network devices for class 12. So as you are now familiar with the evolution of network and Transmission Media now you need to know about network devices for class 12. So here we begin!

Network Devices for Class 12

Network devices are a very important topic of networking. As these devices help to connect various communication channels with each other. We will talk about following network devices:

  1. Modem
  2. RJ45 connector
  3. Ethernet Card
  4. WiFi Card
  5. Hub
  6. Switch
  7. Repeater
  8. Router
  9. Gateway

So now let us explore them in detail.


The first device for Network Devices for Class 12 is the modem. A modem stands for MOdulator/DEModulator. It works on the function process of Modulation and Demodulation.

Modulation refers to converting analog signals to digital signal.

Demodulation refers to the reverse process of modulation.


As you know that computers accept the signals in form of 0s and 1s, considered as digital data. When signals are exchanged between various communication channels and devices, needs to be converted into analogue and digital signals and vice. So the modem helps in this conversion and it is connected at both ends.

The modem at the sender’s side works as modulator and receiver’s side as a demodulator.

RJ45 Connector

This connector is used to attach with twisted pair or ethernet type cables. It connects both ends of the cable. It is a small plastic plug that fits on RJ 45 cables.

RJ45 Connector
RJ45 Connector

Ethernet Card

It is popularly known as Network Interface Card or Network Interface Unit. It provides an interface between the computer and the network.

ethernet card
ethernet card

It is a small circuit board attached to the computer’s motherboard. However, you can also attach expansion NIC for your computer. This NIC has a port to connect ethernet cables using ethernet connectors.

Every ethernet card has its own physical address. This address is known as MAC (Media Access Control) Address.

MAC Address

A MAC address is a unique address that is assigned by the manufacturer of the NIC Card. It is a 6-byte address. Each byte in MAC address is separated by a colon. It looks like:


In this address, first three bytes are manufacturer-id and rest three bytes are card-no. The manufacturer-id is assigned by an International Organization IEEE.

Wifi Card

It is similar like ethernet card that enables a Wi-Fi connectivity for the computers. The Wi-Fi Card is coming wit a small antenna. It is known as wireless NIC.


A hub is a device which is used to connect more than one device in the network. It contains a few ports on it to connect the cables for various device. It is placed at the central position in the network location. It connects devices like workstations, servers etc. It is best suitable for LAN.

Hub - Network Devices for Class 12
Hub – Network Devices for Class 12

These hubs can be either active or passive.

An active hub can extends the network signals using repeaters in the network over geographical distance where as passive hub pass the signal from one computer to another computer without change in short distances.

A hub can have 8,12,or 24 ethernet ports, usually.


A switch can connect different subnetworks. These subnetworks abbreviated as SubNets or LAN segments. By using switch devices the network traffic can be controlled in different segments. It filters, transfers data in a specific way and forward packets between LAN. A switch has more ports compared to a hub.

Switch - Network Devices for Class 12
Switch – Network Devices for Class 12


Sometimes you need to spread your network over geographical distance. The repeater is a device that amplifies the network over geographical distance. It extends the network in long distances for a single run.

These repeaters are of two types:

  1. Amplifier: It just amplifies the the incoming signals over the long distance network.
  2. Signal repeater: It amplifies the signal as well as concurrent noise. It collects the inbound packet and then transmits the data as its coming from the source.


A router is more powerful and intelligent than hub or switch. It has advanced capabilities as it can analyze the data and decide the data is packed and send it to the other network. It can handle huge packets. It can be wired or wireless, both. A wireless router can provides access to many devices like smartphones, and connected devices.

Its looks like a Modem.



It is a device which connects dissimilar networks. It expands the functionality of routers. It is not a device but a node or workstation or computer connected to the network.

In the enterprise, the gateway gives a direction to the traffic from workstation to outside network that is serving the web pages. In homes, the gateway is the ISP that connects the user to internet.

That’s all from the topic Network Devices for Class 12. I hope you understood the concept. If you have anything for me you can leave your comments. Looking to hear something from your side. Thank you for reading this article. Hit the like button and share the article with your friends.

Computer Science Class 12

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