We briefly review the context of the SKA in the panorama of modern Cosmology. The SKA will undoubtedly be one of the most powerful tools for Cosmology during the first half of the XXIst century. Many of the fundamental questions of modern Cosmology, such as the nature of the dark energy and dark matter that dominate the dynamics of the Universe, will be answered by SKA-driven science. Moreover, SKA will shed light on many aspects of large-scale structure growth and galaxy formation as well as fundamental Physics regarding the early Universe, inflation and tests of General Relativity.