Understanding the generations in title of the labradoodle pretty straight forward. F1 are first generation, cross between Labs and Standard Poodles. Then you get into the "b"s. That is Labradoodles mixed with Poodles. The result of these mixes are 1/4 Lab and 3/4 Poodle. The 2 are second generation or Multi-generational. the chart below spells it out well.