Difference Between Analog and Digital Technology

[modulus]

A few days ago, I was reading an article on wikipedia about how musical synthesizers work and I read that initially analog technology was used and later digital technology began to be used.
What I uderstood from analog technology was that only one part of the sound was altered, which affected the sound produced as a whole. For example, we vary the frequency of the sound in such a way that it also changes the amplitude and the pitch, resulting in the emission of a completely new sound.
But, as I read ahead, I figured out that most modern synthesizers synthesize sounds through either 'FMS (Frequency Modulation Synthesis)' or 'PDS (Phase Distortion Synthesis)'. It told me that in FMS just by altering the frequency, we change the sound and in PDS it told me that just by altering the phase angle, the sound was synthesized. Yet, it called this form of synthesis digital technology.
I don't quite understand that, because isn't that the same thing as analog technology (we just alter one thing to synthesize the whole sound)?? So, what exactly is the difference between analog and digital technologies??
In case you need to check, this is the link of the article: http://en.wikipedia.org/wiki/Synthesizer

Any help will be appreciated. Thank you.

 

[DavidSnider]

Analog technology operated on actual waves in real time. Digital technology approximates waves and has a layer of software that allows the user to manipulate them as if they were real waves.

 

[modulus]

Hmmmm... that kind of cleared things up, but, what do you mean by 'operated on actual waves in real time'. The article had something about oscillators... how do those work??

 

[DavidSnider]

Hmmmm... that kind of cleared things up, but, what do you mean by 'operated on actual waves in real time'. The article had something about oscillators... how do those work??

With analog the reason the noise changes is because you changed the properties of the circuit producing the signal. With digital you make a virtual model of a analog signal, manipulate it and then send it to your sound card to be converted from binary data into analog sound waves.

.. and by 'actual waves' I just mean physical. Waves are geometric ideas like circles, and anything real is quantized at some point, but they map to what is observed so well that it's just easier to think of them that way.

 

[DavidSnider]

http://en.wikipedia.org/wiki/Continuous_signal
http://en.wikipedia.org/wiki/Discrete_signal
http://en.wikipedia.org/wiki/Quantization_(signal_processing)

These articles do a pretty good job of explaining what is going on.

 

[cheae]

For the analog format, the translation of data is in electric pulses which varies in amplitude while for the digital format, the translation of data is in the binary format with two distinct amplitudes represent each bit.

Excerpt from the article http://www.differencebetween.net/technology/difference-between-analog-and-digital