Operational Bases were created in the early part of the war on mainly little used civilian airfields. They were provided with facilities such as water, phone, stocks of fuel and ammunition, but were mostly not staffed with permanent RAAF ground crew. The term's usage seemed to change as the war progressed (but that's just my observation). Other related terms include "Maintenance (Repair and Salvage) aerodrome" and "Training Aerodrome". Camden was a training aerodrome.
A parent aerodrome is exactly what it sounds like. A major operational aerodrome with a number of satellite aerodromes or landing grounds attached. It is possible (with aerodromes, anyway) to have a parent field but no satellite "children", however. See also Schofields, Fleurs or Richmond.
A satellite aerodrome is a "child" of a parent aerodrome, normally a major operational airfield, and used primarily to relieve congestion in the circuit area (that's the airspace around the parent where for safety aircraft follow a predetermined approach and departure pattern or 'circuit'). Satellites may also provide other relief, including parking and at times servicing. Satellites and 'dispersal' airstrips can become confused, however at times the relationship was clearly set down. Pitt Town could be considered a satellite of Richmond, for example, or Menangle for Schofields.
Dispersal airstrips were attached to an Aircraft Depot, Aircraft Park or Operational Base, and consisted of landing ground with revetted (faced, embanked, walled) areas for open (but often camouflaged) storage of aircraft. This was a tactical method to disperse aircraft, thereby reducing the effect of enemy targeting a single aerodrome for air attack. Such strips were provided with the bare minimum of services and no permanent hangars or buildings. Cordeaux is a dispersal strip for Albion Park, for example.
An Emergency Landing Ground or ELG is an area of land, prepared and set aside for use by aircraft, but not on a regular basis. As you'd expect, it's for an emergency (engine out, low fuel, bad weather etc). These may be set in paddocks, for example, along strategic air routes. This would not preclude training activities such as "touch and goes" of course. As far as I can tell Tuggerah was such a field, although it may have been considered as or planned to be a satellite (of Fleurs) as well.
Not to be confused with an EAA, which is an emergency alighting area for seaplanes. No "land" required ;-)
A Relief Landing Ground is an area of land which has been prepared for regular use by service aircraft. Again, ripe for confusion with dispersal and satellite airstrips. If I can think of an example I'll let you know.
An Aircraft Depot was an aerodrome where large numbers of aircraft were stored and maintained. In some cases the aircraft were used for training purposes. Bankstown may be an example (I await correction!). Bankstown was many things, an "air base" for the USAAF as well as an "air station" for the RN. It certainly housed many aircraft, some of which were unused, perhaps not even fully assembled at war's end.
An Aircraft Park was an aerodrome where large numbers of aircraft were parked, as in open storage. Such aircraft were used both for operational and training purposes. Menangle was an aircraft park for Schofields, for example. However it was also a dispersal airstrip.
As I wrote this I found overlap everywhere. Whilst some cases are neat and clear-cut, there are many other examples where airfield use became blurred by operational or training needs. Needs also changed as the war progressed.
In any case it's the best set of definitions I can muster right now.
NSW Environment Heritage Study, Aerodromes and Appendix C
Checkout my list of Sydney and surrounding airstrips and airports.