The present review book by Prof., Dr. Lev I. Dorman, Plasmas and Energetic Processes in Geomagnetosphere reflects the development of the geomagnetosphere’s research and applications for the last few decades. The importance and actuality of geomagnetosphere research are based on the following three factors: 1. The geomagnetosphere is the nearest giant natural laboratory, where it is possible via satellites and ground measurements to investigate in detail many different plasmas and energetic processes in space, which are caused by an interaction of high kinetic energy solar wind plasmas and its perturbations (Interplanetary Coronal Mass Ejections - ICMEs, Interplanetary Shock Waves – ISWs, Interplanetary Interaction Regions – IIR), including those frozen in the Interplanetary Magnetic Fields (IMF) with the rotated main geomagnetic field. This interaction leads to the dynamic transformation of magnetic fields in the geomagnetosphere, generation and trapping of high energy particles (which are known as Magnetospheric Cosmic Rays – MCR), and the generation of many types of instabilities and electromagnetic radiations. These processes are in principle similar to processes in magnetospheres of other planets and their moons, in the atmosphere of the sun and other stars, in interplanetary and in interstellar space, and in many different astrophysical objects. This research is an important basis for fundamental space and astrophysical science. 2. Today, technology, economics, navigation, TV, Internet, radio connections, military aspects, and the life of people on our planet are strongly connected to the work of many satellites moving inside the geomagnetosphere. Different processes and MCR in the geomagnetosphere influence the satellites’ work and often lead to satellite malfunctions up to fully destroying their electronics; satellites essentially die in these cases. The described research can be considered as a basis for developing methods of forecasting dangerous situations for satellites in different orbits and to decrease the risk of satellite malfunctions and loss. 3. The interaction of ICME, ISW, and IIR with the geomagnetosphere leads to the generation of big magnetic storms accompanied with a Forbush decrease and precursory effects in Galactic Cosmic Ray (GCR) intensity. These magnetic storms are dangerous not only to satellites, but also to the Earth’s surface in terms of technology, radio connections, car accidents, and human health (e.g., increasing the frequency of infarct myocardial and brain strokes). Investigations of causes of magnetic storms can help to develop methods of forecasting and decreasing the level of magnetic storm hazards. Therefore, the other practical application of this research is connected with the problem of space weather and space climate influence on the technology, radio connections, navigation, transportation, and people’s health on the Earth, which is independent of altitude and geomagnetic latitude.