The purpose of fusion research is the development of the basic principles and technologies of a fusion power plant, which could cover the energy needs of mankind for thousands of years. Fusion gets its energy from the fusion of light nuclei following the sun as precedent. Primary fuel for fusion on earth is deuterium and lithium; the safety characteristics of fusion are favourable; no greenhouse gases are produced; fusion waste can be recycled after typically 100 years. The conditions for fusion are met in hot plasmas, which are confined in toroidal magnetic systems called tokamaks and stellarators. The principles of magnetic confinement in toroidal systems will be described and a few selected physics topics will be discussed in some depth; also the present status of fusion research will be summarised along with the next steps planned.