The Solar X-ray Corona

The X-ray emission from the Sun reveals a very dynamic hot atmosphere, the corona, which is characterized by a complex morphology and a broad range of timescales of variability and spatial structuring. The solar magnetic field plays a fundamental role in the heating and structuring of the solar corona. Increasingly higher quality X-ray solar observations with high spatial (down to sub-arcsec) and temporal resolution provide fundamental information to refine our understanding of the solar magnetic activity and of the underlying physical processes leading to the heating of the solar outer atmosphere. Here, we provide a brief historical overview of X-ray solar observations, and we summarize recent progress in our understanding of the solar corona as made possible by state-of-the-art current X-ray observations.