Physics of the outer atmosphere of the Sun and of stars along their evolutionary track

We discuss the activity of a Co-financed project dedicated to study stellar activity and, more in general, stellar properties, through observations in X-ray, UV, optical etc. bands and through modeling. A key aspect of the project is the study of activity of stars in various phases of their evolution so as to ascertain the role of evolution in determining activity and the role of activity in influencing evolution, e.g. through the significant loss of angular momentum. An even more detailed study, thanks to its proximity, of the Sun is a fundamental part of this project; the relevant information is indeed both important for solar physics `per se' and to help defining with a high level of detail, and therefore of insight, the physical conditions in the solar atmosphere which thus is an important reference for the studies of stellar activity.