The roadmap to a feasible fusion reactor based on the tokamak line is already established. However, options for further improvement are very desirable in order to be ready to meet the future requirements of the energy market. In this respect, stellarators have a significant role to play as candidates for steady state operation reactors.Like tokamaks, stellarators are toroidal confining devices but they show two fundamental differences: the fact that the confining magnetic field is generated by external coils; and the lack of toroidal symmetry. The history of tokamaks shows that from the original concept, solutions have converged into a given range of configurations, and, in fact, all large tokamak are relatively similar. On the other hand most of the stellarators are apparently very different (coil structure, plasma shape, size, ...).The advantage of the higher dimensionality of stellarators has been perceived as a shortcoming, but recent developments, both theoretical and computational, have permitted us to develop improved concepts and design new stellarators with outstanding physics properties. Moreover, most of the devices presently under construction are stellarators.This work is devoted to discuss, firstly, the present role of stellarators in the understanding of basic physical processes in fusion devices, secondly the role of future devices, based on different concept improvements, which will significantly expand the stellarator plasma parameter range, and finally, the potential of the concept as a fusion reactor.