Explore the fascinating world of magnetic hard disk drives and their crucial role in cloud storage through this informative APS Physics conference talk. Delve into the history, components, and technological advancements of HDDs, including their impressive bit areal density growth that often surpasses Moore's Law. Discover the nanotechnology marvels within HDDs, such as 6 nm diameter magnetic grains, sub-25 nm wide magneto-resistive sensors, and airfoils maintaining sub-2 nm gaps. Learn about the physical limits of HDD technology and innovative approaches to push these boundaries, including hermetically-sealed helium HDDs and near-field energy sources. Gain insights into the economic outlook and future challenges facing the HDD industry, and understand why HDDs continue to dominate information storage despite competition from NAND flash memory.