Difference between audio and sound

Difference between audio and sound, Sound is combination of different frequencies present in environment out of which human beings can listen to upto certain frequencies i.e 20hz to 20khz which is known to be audible frequencies and which can be said that when we listen a sound from environment and we process it and then produce it as audible sound then that is called as audio Sound is a mechanical vibration that passes through  different elastic medium . Sound is acostical and mechanical pressure signal,Audio can be used to refer to two things: an electric signal representing sound or an audible sound

Audio is anything audible that has been produced, recorded or processed by something electronic or digital. This could also be referred to as a “sound signal”.

Sound is acoustical pressure which act as longitudnal waveform which is basically combination of Wavelength, Frequency, Amplitude, Pressure, Intensity and speed.When this same sound is processed digitally then that is called as Audio

So audio is a sound, not all sounds are audio.

Here in this diagram we can see a dog is barking , when dog barks it disturms the air molecules present near dog and creates pressure on the molecules as a result of which they start to vibrate in too and fro motion which is called longitudnal waveform and these vibration of molecules takes place at certain frequency i.e (frequency- No of cycles per second) so these vibrations at same frequencies create pressure near human ear and molecules near human ear starts to vibrate a that frequency which is identified by human outer ear and finaly we are able to listen dogs bark.

Here we can see that sound wave form is converted to digital signal or we can say as descrete signal(not continuous) , so this sound wave is not audible to human being because of frequency range ,which is not in 20hz -20khz range so now what we do we convert this sound wave form into audio signal that means continuous into discontinuous signal and then we manipulate and process the signal digitally and produce a processed signal called audio.

This is called descrete signal which is sent through limiter to limit the frequency range and then sampled through sampler according to nyquist theory N/2 or (2fm),example if we have given frqency range but we will limit it to 20hz to 20khz so the highest frequency gets doubled that means 20khz is doubled that means 40khz samples will be send per second which is called as Sampling rate