Natural and Man-Made Plasmas
To put it very simply, a plasma is an ionized gas. A gas into which sufficient energy is provided to free electrons from atoms or molecules and to allow both species, ions and electrons, to coexist.
Lightning is a familiar form of plasma

More Lightning Pictures
Fluorescent lights are a common man-made plasma


Photographs from Osram Sylvania
Microwave and Radio Frequency Plasmas are used in Semiconductor Fabrication

Image of the electron cyclotron resonance (ECR) microwave plasma used in our research.
Blumenthal Research Group