Sterile neutrino overview
The basic theory and experimental hints for light sterile neutrinos at eV$^2$ mass scale are reviewed. Besides the LSND/MiniBooNE, reactor and Gallium anomalies, other recent experimental results searching for light sterile neutrinos are also presented. The existence of the light sterile neutrino is still unclear due to the tension between those experiments. In the next a few years, several worldwide short-baseline neutrino oscillation experiments will start taking data. Hopefully the mystery of sterile neutrino will be unveiled in the near future.