  Neutrino oscillations have become well-known phenomenon; the measurements of
neutrino mixing angles and mass squared differences are continuously improving.
Future oscillation experiments will eventually determine the remaining unknown
neutrino parameters, namely, the mass ordering, normal or inverted, and the
CP-violating phase. On the other hand, the absolute mass scale of neutrinos
could be probed by cosmological observations, single beta decay as well as by
neutrinoless double beta decay experiments. Furthermore, the last one may shed
light on the nature of neutrinos, Dirac or Majorana, by measuring the effective
Majorana mass of neutrinos. However, the neutrino mass generation mechanism
remains unknown. A well-motivated phenomenological approach to search for new
physics, in the neutrino sector, is that of non-standard interactions. In this
short review, the current constraints in this picture, as well as the
perspectives from future experiments, are discussed.
