Magnetohydrodynamics describes dynamics in electrically conductive fluids. These occur in our environment as well as in our atmosphere and magnetosphere, and play a role in the sun's interaction with our planet. In most cases these phenomena involve turbulences, and thus are very challenging to understand and calculate. A sound knowledge is needed to tackle these problems. This workgives the basic information on turbulence in nature, comprising the needed equations, notions and nuemrical simulations.The current state of our knowledge and future implicationsof MHD turbulence are outlined systematically. It is indispensable for all scientists engaged in research of our atmosphere and in space science.