Digital logic, or boolean logic, is the means by which digital electronic devices handle data. But in order for this to work, all the components of the device must interpret the same signals in the same way.
In each logic family, the basic building blocks of each device are the same. In CMOS, this building block is the MOS transistor.
Devices belonging to different logic families cannot usually be connected without an interface, since the voltages interpreted as 'true' or 'false' (or 1 or 0), as well as the supply voltages, will differ.