This online training module, led by Dr. Roland Bourdeix, explores fundamental concepts in coconut diversity, focusing on the distinction between phenotype and genotype, and the strategies of in situ versus ex situ conservation. A detailed glossary introduces key terms, such as accession, genotype, phenotype, in vitro, cryoconservation, and hybridization, providing a scientific foundation for learners. The course illustrates how environmental conditions strongly influence coconut phenotype, even when genetic material remains constant. For instance, the Madang Brown Dwarf variety produced robust fruits in Papua New Guinea but yielded small, poor-quality fruits in degraded soils in Côte d'Ivoire—yet improved again when replanted in fertile Vanuatu. Such examples highlight the crucial interaction between genotype and environment in coconut development. Coconut palms produce 12–16 fronds annually, and each frond's axil may develop an inflorescence. These inflorescences carry both male and female flowers: the female flowers are round and located near the base, while male flowers are smaller, elongated, and found at the top of each spikelet. Pollination occurs when male flowers release pollen grains, mostly in the morning, which can fertilize receptive female flowers. Depending on the variety, pollination can be self- or cross-fertilizing, influenced by the timing overlap of male and female flowering phases. For instance, Dwarf varieties often self-pollinate due to simultaneous flower opening, while Tall varieties typically cross-pollinate because of a delay between male and female phases. Only a fraction (20–30%) of female flowers develop into mature coconuts due to factors like lack of pollen, pollinators, water stress, or nutrient deficiencies. The course highlights “button shedding”, or the early drop of unfertilized female flowers, which can be minimized through proper irrigation and fertilization. Four main flowering behavior groups are identified, ranging from stric