NCERT Class 12 Computer Science Computer Science: Chapter 11 — Data Communication
This chapter introduces the concept of Data Communication, defining data as any form of digital information like text, images, audio, or video. Communication is the process of sending or receiving this data. Data communication, therefore, is the exchange of data between two or more connected devices over a communication medium. The chapter highlights that these devices, such as computers and mobile phones, must be capable of both sending and receiving data. Figure 11.1 illustrates a simple network connecting devices like computers, printers, servers, and switches. It further breaks down data communication into five essential components: sender, receiver, communication medium (or transmission media), the message itself, and protocols, which are the rules governing the communication process. The sender is the device initiating data transmission, while the receiver is the device that accepts the data. These components are crucial for establishing a functional network for data exchange, forming the foundation for understanding more complex networking concepts in computer science.
Quick info
| Board | CBSE / NCERT |
|---|---|
| Class | Class 12 |
| Subject | Computer Science |
| Book | Computer Science |
| Chapter | Chapter 11 — Data Communication |
| Language | English |
| PDF type | NCERT Textbook |
| Session | CBSE 2026 |
| Reading time | 2 minutes |
| Word count | 303 |
Learning outcomes
- Understand the definition and scope of data communication.
- Identify the key components involved in data communication.
- Differentiate between sender and receiver roles in a network.
- Recognize the importance of communication media and protocols.
Vocabulary
| Word | Meaning |
|---|---|
| Data | Any text, image, audio, video, and multimedia files. |
| Communication | An act of sending or receiving data. |
| Data Communication | The exchange of data between two or more networked or connected devices. |
| Networked | Connected in a network. |
| Communication Medium | The channel through which data is transmitted. |
| Sender | A device capable of sending data over a network. |
| Receiver | A device capable of receiving data from the network. |
| Nodes | Sender and receiver in computer communication. |
| Protocols | Rules to be followed during communication. |
| Transmission Media | Another term for communication media. |
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Practice questions
- What is data? Answer: Data can be any text, image, audio, video, and multimedia files.
- Define communication. Answer: Communication is an act of sending or receiving data.
- What is data communication? Answer: Data communication refers to the exchange of data between two or more networked or connected devices.
- List the five essential components of data communication. Answer: The five essential components are sender, receiver, communication medium, message, and protocols.
- What is the role of a sender in data communication? Answer: A sender is a device that is capable of sending data over a network.
- What is the role of a receiver in data communication? Answer: A receiver is a device that is capable of receiving data from the network.
Practice MCQs
Q1. Which of the following is an example of data?
Explanation: Data encompasses all digital forms of information, including text, audio, video, and multimedia files.
Q2. The act of sending or receiving data is known as:
Explanation: Communication is defined as the process of exchanging information, which in this context refers to sending or receiving data.
Q3. Data communication refers to:
Explanation: Data communication specifically involves the transfer of data between two or more devices that are connected.
Q4. Which of the following is NOT a component of data communication?
Explanation: While the internet is a network that facilitates data communication, it is not one of the five fundamental components listed in the chapter (sender, receiver, medium, message, protocols).
Q5. In computer communication, the sender and receiver are also known as:
Explanation: In the context of computer networks, both the sending and receiving devices are referred to as nodes.
Q6. What are the rules called that must be followed during communication?
Explanation: Protocols are the set of rules and conventions that govern how data is transmitted and received between devices in a network.
Frequently asked questions
What is the basic definition of data communication?
Data communication is the exchange of data between two or more connected devices over a communication medium.
What are the five essential components of data communication?
The five essential components are sender, receiver, communication medium, message, and protocols.
Can a mobile phone act as a sender or receiver?
Yes, a mobile phone can act as both a sender (sending data) and a receiver (receiving data) in data communication.
What is the difference between communication medium and transmission media?
There is no difference; they are interchangeable terms for the channel through which data is transmitted.
What is the role of protocols in data communication?
Protocols are rules that ensure orderly and efficient communication between devices, defining how data is formatted, transmitted, and received.
What are nodes in a computer network?
Nodes are the devices in a network that can send or receive data, essentially referring to the sender and receiver.
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NCERT Class 12 Computer Science — Computer Science — Chapter 11 — Data Communication. Verified by NCERT Help Editorial Team. Reviewed on 29 Jul 2026. Last updated 10 Aug 2026.