Although plasmas cover an enormously wide range of parameters, and although the technologies and their applications differ strongly, several general mechanisms and technological processes, such as dimensionless parameters, generation and controlling of plasmas by particle wave interactions, plasma‐wall‐interactions, surface engineering and diagnostics are quite similar. Microwave technology offers both low temperature plasma applications and plasma heating for the fusion reactors. The interaction of plasmas with the nearby surfaces and the resulting material changes follow the same general mechanisms in low, as well as in high temperature plasmas, and their diagnostics are similar.