CMOS is a technology to construct integrated circuits. The CMOS technology is mostly used in digital circuits to convey digital logic signals such as digital logic ICs, encoders and decoders, multiplexer etc. But the interesting fact is only a few CMOS ICs are actually completely Digital in nature. In most cases the CMOS technology is used in digital analog combined circuit.

CMOS also have many application in analog field such as fabricating the ICs of Operational Amplifier, Comperator and it has wide range of use in RF circuits.

Basically the difference between the Analog and Digital CMOS is based on the application. In digital circuit CMOS will work with 1 and 0 input and will produce 1 and 0 output. In analog circuit CMOS will work with variety level of input and produce 1 and 0 or different level output.

In Digital CMOS, the N and P transistors are tiny, and getting tinier, year by year . Each stage is over driven, thus has a binary stage output.

In Analog CMOS, input N and P transistors are small, output transistors are larger.

Overall negative feedback keeps most all stages within a fairly linear operating region.