Collective flow measurements at RHIC energies

Recent experimental results on collective flow measurements from relativistic heavy-ion collider (RHIC) are presented and discussed to study high-temperature and high-density quark-nuclear matter, Quark Gluon Plasma (QGP) especially focusing on bulk properties, such as freeze-out parameters, temperature, chemical potential, collective expansion, azimuthal event anisotropy measurements. Their relations to the various correlation and fluctuation studies are also discussed, including initial geometrical and E- and B-field conditions as well as possible collective flow evolution that could even be developed in small systems. Current results and understandings from the beam energy scan program (BES) and future plans are discussed and reviewed