How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

The resolution of an analog-to-digital converter (ADC) dictates how many discrete voltage levels it can recognize and output. This is determined using binary math, where the total number of levels equals 2 raised to the power of the number of bits. For an 8-bit ADC, the calculation is 2^8, which equals 256 different input levels (ranging from 0 to 255). The gain of an input amplifier might change the physical voltage range being sampled, but it has absolutely no effect on the number of discrete digital levels the ADC itself can encode.