  The Sun, as an active star, is the driver of energetic phenomena that
structure interplanetary space and affect planetary atmospheres. The effects of
Space Weather on Earth and the solar system is of increasing importance as
human spaceflight is preparing for lunar and Mars missions. This review is
focusing on the solar perspective of the Space Weather relevant phenomena,
coronal mass ejections (CMEs), flares, solar energetic particles (SEPs), and
solar wind stream interaction regions (SIR). With the advent of the STEREO
mission (launched in 2006), literally, new perspectives were provided that
enabled for the first time to study coronal structures and the evolution of
activity phenomena in three dimensions. New imaging capabilities, covering the
entire Sun-Earth distance range, allowed to seamlessly connect CMEs and their
interplanetary counterparts measured in-situ (so called ICMEs). This vastly
increased our knowledge and understanding of the dynamics of interplanetary
space due to solar activity and fostered the development of Space Weather
forecasting models. Moreover, we are facing challenging times gathering new
data from two extraordinary missions, NASA's Parker Solar Probe (launched in
2018) and ESA's Solar Orbiter (launched in 2020), that will in the near future
provide more detailed insight into the solar wind evolution and image CMEs from
view points never approached before. The current review builds upon the Living
Reviews paper by Schwenn from 2006, updating on the Space Weather relevant
CME-flare-SEP phenomena from the solar perspective, as observed from multiple
viewpoints and their concomitant solar surface signatures.
