Explore the complex phenomenon of localisation-delocalisation transition through the lens of Fock space in this 39-minute lecture by Subroto Mukherjee. Delve into the stability of quantum matter in and out of equilibrium at various scales, examining mechanisms that constrain many-body dynamics in Hilbert space. Gain insights into cutting-edge concepts like Many-body localization (MBL), Floquet MBL, Dynamical Freezing, and Hilbert Space Fragmentation. Discover how these mechanisms potentially underpin novel phases of quantum matter and their implications for quantum technologies. Part of a comprehensive program organized by leading experts in the field, this talk bridges condensed matter physics, statistical mechanics, quantum field theory, and advanced mathematics to address fundamental questions about the behavior of coherent quantum systems under external drives.