Digital Electronics is a subset of Electronics that uses voltage levels (defined by the LogicFamily) to represent Binary values.
The computer sitting in front of you is a myriad of digital electronics. Digital designers are not (supposed to be) worried about the technicalities of AnalogElectronics, but it is often the case that analog effects (crosstalk, ground bounce) become problems, especially in high-speed designs (>100MHz).
2 pages link to DigitalElectronics:
