What is Data Communication?
You now know how a network is shaped and which devices it is built from. This chapter is about what a network is for: getting data from one device to another. Start with something you do every day without thinking — talking.
1Communication
Talking to a friend is communication. So is writing a letter, waving from across the road, or a teacher writing on the board. In every one, something is passed from one side to the other and understood there.
2Data communication
The data can be in any form: text, numbers, images, audio or video. You are part of data communication whenever you:
- send a WhatsApp message or a photo,
- make a video call,
- print from a laptop to a Wi-Fi printer,
- pay a shop by UPI,
- let a smartwatch send your steps to your phone.
Data communication is the same idea as two people talking. The lab shows both, side by side. Press ▶ Play and watch which part of the conversation lights up.
Press ▶ Play, then switch to computers and play again. Drag sideways to turn.
3The same five parts
Did you spot it? Both conversations need the same five things. Each one has a name, and together they are called the components of data communication.
| Component | Two people | Two computers |
|---|---|---|
| 📤 Sender | Riya, who speaks | The computer that sends |
| 📥 Receiver | Aman, who listens | The computer that receives |
| ✉️ Message | “Namaste!” | The data: “Hi Aman!” |
| 〰️ Communication media | The air that carries the sound | The network cable |
| 🤝 Protocol | A language both of them know | Rules both computers follow |
The next lesson takes these one at a time — and lets you remove each one to see why it is needed.
4Check yourself
Which of these is data communication?
In a conversation between two people, which part plays the role of the protocol?