Plasma is ionized gas
This term will mainly occur when it comes to verschullende types of television screens. The display of images is done by a plasma screen by a few hundred thousand minuscule luminous dots or pixels. This gives a high resolution and ability to display lots of details. At startup and shutdown make a "clicking" sound (this is due to the temperature differences). Together with the LCD screens plasma is seen as the successor of the classic TV screens with CRT. A plasma screen provides an enclosed space for an (electrical) voltage between 2 electrodes. A gas (xenon or neon) is ionized and this emits UV Foton. See the inside of a plasma screen: