This book is a compilation of important topics that document the results of research in olive and grapevine genetics, as an addition to the complete compendium of the present biodiversity of both species with an insight into molecular mechanisms accountable for their important and desirable traits. It covers a wide range of distinct topics related to olive and grapevine genetics, without any strict limitation, keeping the title as a loose frame for the limitless science of olive and grapevine studies. The book talks about the distinct levels of genetic variability, revealing the remains of still existing wild populations and treasures of overlooked local peculiarities, constructing the network from plant to product and back to the start, to the hearth of all questions asked and the answers hidden in genetics.