||Known as the "Fourth State of Matter", a plasma is a substance in which many of the atoms or molecules are effectively ionized, allowing charges to flow freely. Since some 99% of the known universe is in the plasma state and has been since the Big Bang, plasmas might be considered the First State of Matter. Plasmas have unique physics compared to solids, liquids, and gases; although plasmas are often treated as extremely hot gases, this is often incorrect. Examples of plasmas include the sun, fluorescent light bulbs and other gas-discharge tubes, very hot flames, much of interplanetary, interstellar, and intergalactice space, the earth's ionosphere, parts of the atmosphere around lightning discharges, laser-produced plasmas and plasmas produced for magnetic confinement fusion.
Types of plasmas include - Astrophysical, Collisionless, Cylindrical, Electrostatically Neutral, Inhomogeneous, Intergalactic, Interstellar, Magnetized, Nonneutral, Nonthermal, Partially Ionized, Relativistic, Solid State, Strongly Coupled, Thermal, Unmagnetized, Vlasov and more.