2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/98769Rich clusters of galaxies, the largest virialized systems known, provide a powerful tool for the study of cosmology. Some of the fundamental questions that can be addressed with clusters of galaxies include: how did galaxies and large-scale structure form and evolve? What is the amount, composition and distribution of matter in the universe? I review some of the studies utilizing clusters of galaxies to investigare, among others: - The dark matter on clusters scale and the mean mass-density of the universe; - The large-scale structure of the universe; - The peculiar velocity field on large scales; - The mass-function of groups and clusters of galaxies; - The constraints placed on specific cosmological models using the cluster data.compressed PostScript, to appear in the Proceedings of 11th Potsdam Cosmology Workshop on "Large Scale Structrure in the Universe", 1994; for the figures contact neta@astro.princeton.eduAstrophysicstext