The primary function of a Bit Analog to Digital Converter (ADC) is to receive an analog input signal from a physical source, such as a sensor, microphone, or thermometer, which represents a continuous value. This continuous value is then converted into a digital format that can be processed by electronic devices like computers and smartphones. The ADC does this conversion by sampling the analog signal at regular intervals and quantizing it into discrete digital values, represented as binary digits (bits).