Natural diversity has been extensively used to understand plant biology and improve crops. However, studies were commonly based on visual phenotypes or on a few measurable parameters. Nowadays, a large number of parameters can be measured thanks to next generation sequencing, metabolomics, proteomics, and transcriptomics thus providing an unprecedented resolution in the detection of natural diversity. This enhanced resolution offers new possibilities in terms of understanding plant biology. Technology advances also contribute to a better assessment of the biodiversity loss currently taking place. Hence, the topic presents an overview on efforts for maintaining biological diversity in crops, on possibilities offered by recent technologies in the assessment of natural variation, and ends with examples of the diversity found even at the cellular level.