2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/167882In this paper, we review some of the properties of dense molecular cloud cores. The results presented here rely on three-dimensional numerical simulations of isothermal, magnetized, turbulent, and self-gravitating molecular clouds (MCs) in which dense core form as a consequence of the gravo-turbulent fragmentation of the clouds. In particular we discuss issues related to the mass spectrum of the cores, their lifetimes and their virial balance.Paper of invited talk at the 2008 french astronomical society meeting (SF2A-2008). 4 pages; 4 figures. A few typos corrected in the text and referencesAstrophysicstext