Remember analog vs. digital? In case you did not see it, you can find it here. The world data is in analog form but computers can only process digital form. That’s why there is a need to convert analog to digital and vise versa.
Let’s see audio system for example, your mic will capture your voice, turn sound waves to a series of 0s and 1s (analog to digital) send it to the speaker then reproduce the sound waves again through digital to analog converter.
Sound systems used to be pure analog circuits, but now in smart phones it is very difficult to build slim phones with analog circuits. That is one of the reasons why ADC and DAC are important.
