The nature of nanoscience and nanotechnology (collectively, nano) are discussed as important examples of the modern sciences and technologies that are having an increasing impact on all aspects of life. In this Position paper, general proposals are made for the levels of understanding of nano that might be attained by whole populations. The ideas that should be addressed in those levels of understanding are reviewed. The scope and limitations of formal and informal avenues to the attainment of such understanding are outlined. Proposals are made for the aspects of nano that are best conveyed by the different media available for informal provision and illustrated from the scant documentation of contemporary practice. Last, some substantial issues for further research and development are identified.