  Since the observation of $\Lambda$ global polarization at RHIC, indicating
the most vortical fluid ever observed so far, many experimental and theoretical
progresses have been made in understanding of vorticity and polarization
phenomena in heavy-ion collisions. But there still exist open questions which
are currently being studied. In these proceedings, recent experimental results
on global and local polarization of hyperons in heavy-ion collisions are
reviewed.
