Abstract

This review synthesises our current understanding of galaxy assembly, focusing on the powerful diagnostic tools of chemo-kinematics derived from stellar absorption spectra. We begin by contrasting the hierarchical merging paradigm, a cornerstone of the CDM cosmological model, with the outdated monolithic collapse theory. We then detail the methodologies of Galactic Archaeology, where stellar populations serve as fossils, preserving the kinematic and chemical histories of their formation environments.