Abstract
Globular clusters are systems made up of hundreds of thousands, or even millions, of stars, held together by gravity. Long considered very simple systems, made up of stars of the same age and with the same chemical properties, they now reveal a complexity that remains unexplained. In our Galaxy, more than 150 globular clusters have been identified. They help us to understand the formation and evolution of the Milky Way, as well as the way in which visible and dark matter are distributed within it.
