[en] This article discusses our present understanding of the nature of neutrinos as gleaned from experimental particle physics. Sometimes this information comes indirectly, as was the case when the neutrino was first proposed as a particle; quite often, it comes directly from the observation of neutrinos interacting with matter. There are several experimental approaches to determine whether some or all neutrinos have finite mass; although hints exist, there is no unassailable evidence from particle physics experiments that neutrinos do have finite mass