What is the difference?
As we embrace the KISS principle (Keep It Simple & Stupid), we could have used Analog & Digital instead.
- By Continuous, we mean Analog
- By Discrete, we mean Digital
Although both are data, we want to distinguish between their nature for a better understanding.
Usually, data is a time series (it happens while time moves on and on).
However, signal theory must consider time series and frequency series.
The glossary page explains more about the time domain and frequency domain.
As the principle is the same, for simplicity, we will only consider data as a time series at the moment.
Continuous Data
The measured data values are endless when you measure a signal continuously with a recorder such as a plotter. In theory, you can divide time into infinity (because time is also continuous data).
Two measurements at the time of 1 second and the time of 2 seconds will have a value of 0,5 seconds in between.
Again, between 1 second and 0,5 seconds, you will have a value of 0,25 seconds.
We can go on to infinity 0,125 – 0,0625 – 0,3125 … -> infinity.
Examples of continuous data are temperature, weight, height, speed, etc.
Everything you can measure with a measuring instrument is continuous data. See the table hereafter.
| Continuous Data | Measuring instrument |
| Temperature | Thermometer |
| Weight | Weight scale |
| Height | Ruler |
| Speed | Velocity meter |
Discrete Signal/Data
We have seen that time can be divided into infinity because it is also continuous data or signal. However, some data is undividable into infinity. This data we call discrete data.
Examples are easy.
- The number of children you count in a classroom.
- The number of trees you count in a park.
- The number of cars you count in carpark
We do not have measurement instruments to measure this kind of data. Discrete data we have to count (or the measurement instrument would always be a counter), and the result is always a finite value. You cannot have a half-child, a half-tree, or a half-car. There is nothing in between the discrete values.
DAB(+)
As DAB(+) is a digital system, we will often encounter discrete data or signals. The above knowledge can help us better understand the DAB(+) principles we explain on “localdab.org.”