As described under “About the Breed,” the Australian Labradoodle is a crossing of not only Labrador Retriever and Poodle, but additional breeds as well, to achieve the desired characteristics.

In contrast, the “regular” Labradoodle (not meant disparagingly, but only for the sake of clarification) is always limited to a crossing of just the Labrador Retriever and Poodle.

I would like to elaborate a bit more on this:

F: The "F" stands for "filial generation". "F1" means "first generation" and is a common scientific term. In the Labradoodle breed, it is the term for the first cross between a purebred Poodle and a purebred Labrador Retriever. The results are different because this mating is not two "same" dogs or dogs that resemble each other. F1- Labradoodles are usually moderate to low shedding.

B: The additional "B" refers to backcrossing, i.e. a F1- Labradoodle, as described above, is crossed, resp. backcrossed, to a purebred Poodle. Again, the results are different, because again two unequal dogs are mated. F1B Labradoodles are usually low to no shedding if both parents are non-shedding and often have a hair or fleece coat.

Australian Labradoodle: The Australian Labradoodle carries the DNA of the Labrador, the Poodle and the Cocker Spaniel (American or English). (The other breeds crossed in at the beginning are no longer detectable in the DNA, respectively negligible). The resulting dogs will have the same characteristics, although some matings will produce a more mixed litter. An Australian Labradoodle can be bred by crossing a Poodle with an Australian Labradoodle, a Cockapoo with an Australian Labradoodle or a Labradoodle with a Cocker Spaniel.

Australian Labradoodles and Multigen Australian Labradoodles typically have a non-shedding coat when both parents are non-shedding (as much as a dog can be non shedding).

Multigen Australian Labradoodles (Multigenerational): A Multigen Australian Labradoodle is produced by mating two Australian Labradoodles. 

Purebred Australian Labradoodle: The Merriam-Webster dictionary first defined the term "purebred" in 1852 as "bred from members of a recognized breed without admixture of other blood for many generations". The AKC (American Kennel Club) requires four generations of like-to-like matings.

The ALAA uses these two references in the definition of a purebred Australian Labradoodle. Once an Australian Labradoodle has been crossed with an Australian Labradoodle for four generations, it is considered purebred.