Electronics is broadly grouped into two areas: Analogue and digital. Analogue is the area that guitar effects and amplifiers fall into, it deals with continuously varying waveforms like a guitar signal.
Digital electronics deals with two signal levels: 0 and 1 as in computers, this is mapped on to the electronics as voltage levels, one common standard being 0 volt for a 0 and -5 volt for a one.
Logic is a discipline in mathematics which deals with combining of the 0 and 1 in terms of operators like AND, OR, NOT etc ie Boolean algebra which is what computers use to make the decisions they do (when programmed properly)
Digital electronics therefore is the design of electronic circuits to implement boolean logic.
To design a microprocessor you need to know digital electronic logic.
Hope that clarifies things, "digital logic" probably wasn't the correct term to use digital electronics and Boolean algebra, or logic for short, is a better description.
Keith