ExFreight,
As CR2 pointed out, different terminology in different parts of the world and even then you can throw in the odd military terms to boot. For example in the RAF (I should think the RAAF is the same):
Basic Wt = Empty wt of a/c + flt crew + residual fuel
Variable load = Anything over and above the "basics" which are required
on the a/c to complete a task (role equipment, additional
crew members, crew bags etc)
The sum of Basic Wt + Variable load = Aircraft Prepared for Service or APS Weight.
APS (or DOW) + Payload = ZFW
ZFW + Fuel = Actual Take Off Weight (an allowance is made for fuel burnt during taxying so at T/O fuel on board should be sector fuel).