In digital sound recording, an analogue sound wave is converted into a digital representation through the process of sampling and encoded. The Analogue-to-Digital Converter (ADC) is responsible for this process. The ADC samples the analogue wave, Sampling is a process which involves taking regular measurements of the amplitude of the sound wave at fixed intervals. Encoding is the process of converting the sampled values into a binary number. The resulting digital values are stored as binary numbers and can be later reconstructed back into an analogue wave form. The more samples that are taken per second, the higher the quality of the digital representation will be 

The sample rate refers to the number of samples of audio per second that are recorded in digital form. The sample rate is expressed in Hertz (Hz) and determines the quality and clarity of the audio signal. A higher sample rate results in a higher quality, more detailed representation of the original audio signal, while a lower sample rate results in a lower quality, less detailed representation. In general, CD-quality audio (16 bits) has a sample rate of 44.1 kHz, while high-resolution audio has a sample rate of 96 kHz or higher. DVDs are 24 bits.

Telephone networks use a sample rate as low as 8 kHz