The field of solar physics and solar—terrestrial relation, now called space weather, is evolving rapidly. As in the first edition, it is assumed that it is inevitable for the reader to get some basic knowledge in solar physics since the Sun is the main driver for space weather The term space weather itself has been gaining more and more attention during the past years as our society becomes more and more dependent on satellites, which are vulnerable to varying conditions in space. Space weather efforts and investigations are being made all over the world and more and more is known about the complex relations of processes on the Sun and the Earth and its space environment. The term space climate nowadays includes the long-term variations caused mainly by the Sun on the Earth and the interplanetary space. As in the first edition of the book, this edition also covers these topics but new chapters have been introduced, e. g. , a chapter on real-time space weather forecasts and some main space weather data sources. All the chapters have updated information, taking into account the results of new satellite missions and telescopes. The book also includes a great amount of new literature (more than 340 original citations) so that the reader is able to go into more details, if required in the respective chapters.