  Non-geometry has been introduced when considering a new type of string
backgrounds, for which stringy symmetries serve as transition functions between
patches of the target space. Then, some terms in the potential of
four-dimensional gauged supergravities, generated by so-called non-geometric
fluxes, have been argued to find a higher-dimensional origin in these
backgrounds, even if a standard compactification on those cannot be made. We
present here recent results clarifying the relation between these two settings.
Thanks to a field redefinition, we reformulate the NSNS Lagrangian in such a
way that the non-geometric fluxes appear in ten dimensions. In addition, if an
NSNS field configuration is non-geometric, its reformulation in terms of the
new fields can restore a standard geometry. A dimensional reduction is then
possible, and leads to the non-geometric terms in the four-dimensional
potential. Reformulating similarly doubled field theory, we get a better
understanding of the role of the non-geometric fluxes, and rewrite the
Lagrangian in a manifestly diffeomorphism-covariant manner. We finally discuss
the relevance of the field redefinition and the non-geometric fluxes when
studying the non-commutativity of string coordinates.
