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In hybrid genetics, there are varying classes. the original Lab to poodle is called and F1 labradoodle
An F1 bred to an f1 is called an f2
an F1 bred back to either a lab or a poodle (Most often poodle) is an F1b
There are many different levels and the higher you go the more complcated it gets. So no, that's not a silly question at all!
The breed recognized as Labradoodles in Australia has as many as 6 different breeds infused into them. Some American breeders are doing that, but most like myself stick to the lab x poodle or f1 back to poodle.

The reason I prefer to stick with the original generation is that it's the one where you're eliminating the most genetic problems and taking the best advantage of "hybrid vigor". Many genetic problems require that both parents carry the gene to pass it on... so in using 2 distinctly different breeds, you eliminate the possibility of those that one or the other breed doesn't have.