High Quality Content by WIKIPEDIA articles! States of matter are the distinct forms that different phases of matter take on. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma. Further states are possible but do not normally occur in our environment: Bose–Einstein condensates, neutron stars. Other states, such as quark-gluon plasmas, are believed to be possible. Much of the baryonic matter of the universe is in the form of hot plasma, both as rarefied interstellar medium and as dense stars and quantum spin liquid.