- 2078 Kartik · 5 marks
Data versus signal
Short answer
Data is raw abstract information like voice or text; a signal is its physical representation such as a varying voltage or digital pulses for transmission. Data and signal types are independent.
Differentiate data and signal with two examples of each.
Data is raw information in a form that is stored or processed. A signal is the electrical, optical or electromagnetic representation of data used to carry it over a medium. Data is turned into a signal before transmission.
| Point | Data | Signal |
|---|---|---|
| Meaning | Entity that carries information | Physical wave that carries data |
| Form | Analog or digital values | Analog or digital waveform |
| Where used | Stored and processed in the computer | Transmitted on the channel |
| Nature | Abstract, not tied to a medium | Electrical/optical/EM; has amplitude, frequency, phase |
| Conversion | Encoded into a signal by the transmitter | Decoded back into data by the receiver |
Examples
- Analog data: voice, temperature readings. Digital data: text in ASCII, a stored file of 0s and 1s.
- Analog signal: the varying voltage of a telephone line (or an AM wave). Digital signal: the +5 V / 0 V pulse train on a computer bus, or the Manchester-coded pulses on Ethernet.
A digitised voice (digital data) can be sent on an analog signal using a modem, so the data type and the signal type are independent.
✓ Answer checked by Claude Opus 5.5 (high effort)
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