Difference between analogue data and digital data
Analogue data is represented in a continuous form, as contrasted with digital data having discrete values.
Data that is recorded in a form that is similar to its original structure. Contrast with digital data, Analogue signals use continuously variable electric currents and voltages to reproduce data being transmitted.
Need for conversion between analogue and digital data
Since data is sent using variable currents in an analogue system, it is very difficult to remove noise and wave distortions during the transmission. For this reason, analogue signals cannot perform high-quality data transmission.
On the other hand, digital signals use binary data strings (0 and 1) to reproduce data being transmitted. Noise and distortions have little effect, making high-quality data transmission possible.