Abstract
Stars play an essential role in the history of our Universe. Stars synthesize heavy elements such as oxygen and carbon, which are essential for life. Stars also inject energy into galaxies in the form of radiation and motion. Finally, stars orbit planets whose temperature can be greatly affected by the star's radiation. The characteristics of stars, such as their lifetime and luminosity, are highly dependent on their mass. That's why it's vital to know the mass distribution of stars. How many " big stars" are there and how many " small stars" ? The presentation will focus on the issues at stake, the observational data and the main ideas that could explain the mass distribution of stars.
