  The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) studies
properties and phase transitions of nuclear matter in various nucleus-nucleus
collisions at center-of-mass energies per nucleon collision
$\sqrt{s_{NN}}=7.7$-200 GeV. With a fixed target made of gold foils installed
inside the beam pipe, STAR also starts to explore high baryon density regime
($\mu_B\approx420$-720 MeV) at $\sqrt{s_{NN}}=3.0$-7.7 GeV. A few selected
results reported by the STAR collaboration at the Quark Matter 2018 (QM2018)
conference are described in these proceedings.
