The last 20 years have greatly improved the feature set and portability of electronics and anything which does or can contain electronics.

Nonetheless, most people don’t know what the word digital means. In this multi-part series, I will explain the difference between digital and analog, why digital processing is better than analog, and why some analog processing will never go away.

The words analog and digital are both adjectives. What types of nouns do they generally modify?


A signal is anything that has a numeric value that varies with time.

So, for example, naturally occurring things such as:

force / torque
angle/angular speed/angular acceleration
light intensity

are all signals.

Each of these things varies with time. For example, the temperature measured at Chicago O’Hare airport varies both with the hour of the day and with the day of the year.

In addition, several artificial constructions are also signals:

stock prices
votes (per hour) in an election
traffic rates on the Internet

Gadgets are what you think they are: electronic devices, but also appliances, machines, etc.

Examples of gadgets are:

audio recorder/players
video recorder/players

Engineers and mathematicians refer to gadgets (or their component building-blocks) as systems.

It should be noted that a gadget being analog or digital comes down to whether it processes analog signals or digital signals.

In the next post, I’ll explain the characteristics of analog signals and gadgets. In a future post, I will explain characteristics of digital signals and gadgets.