Wojciech Hubert Zurek discusses the emergence of classicality from quantum mechanics through decoherence and einselection. Decoherence arises from environmental interactions that destroy quantum coherence between pointer states, leading to einselection, a process that selects stable states and eliminates nonlocal "Schrödinger cat" states. This process enforces classicality by restricting the Hilbert space, allowing classical trajectories and effective wavepacket collapse. Einselection creates effective superselection rules, enabling classical reality through stable pointer states. The environment's role as a witness allows classicality to emerge as a property of these states, which can be "found out" without re-preparation. Envariance, a new symmetry, explains quantum ignorance and leads to Born's rules and reduced density matrices. The existential interpretation views observers as open quantum systems, emphasizing information acquisition. Quantum Darwinism highlights the redundancy of pointer states in the environment, quantifying classicality. Decoherence and einselection provide a framework for understanding classicality, with envariance offering a fundamental resolution of interpretational issues. The paper reviews progress in decoherence, einselection, and the emergence of classicality, emphasizing the role of information and the environment in quantum mechanics.Wojciech Hubert Zurek discusses the emergence of classicality from quantum mechanics through decoherence and einselection. Decoherence arises from environmental interactions that destroy quantum coherence between pointer states, leading to einselection, a process that selects stable states and eliminates nonlocal "Schrödinger cat" states. This process enforces classicality by restricting the Hilbert space, allowing classical trajectories and effective wavepacket collapse. Einselection creates effective superselection rules, enabling classical reality through stable pointer states. The environment's role as a witness allows classicality to emerge as a property of these states, which can be "found out" without re-preparation. Envariance, a new symmetry, explains quantum ignorance and leads to Born's rules and reduced density matrices. The existential interpretation views observers as open quantum systems, emphasizing information acquisition. Quantum Darwinism highlights the redundancy of pointer states in the environment, quantifying classicality. Decoherence and einselection provide a framework for understanding classicality, with envariance offering a fundamental resolution of interpretational issues. The paper reviews progress in decoherence, einselection, and the emergence of classicality, emphasizing the role of information and the environment in quantum mechanics.