Analog to Digital Converter (ADC) is used to convert an analog signal to a digital signal. The input voltage range of the converter is divided into R of the same intervals. This is the so-called converter resolution. At the output of the converter we get a value that determines in which voltage range the input is. The output value is expressed in binary system, as a sequence of bits (digits 0 or 1). If we have an n bit converter, then its resolution is equal to R = 2n.
Below we have an 8-bit converter measuring voltages in the range of 0V ÷ 5.12V. The input voltage is converted to one of 256 (0÷255) discrete values.