Western Digital is a pure-play hard disk drive (HDD) company following its February 2025 separation from Sandisk, which retained the NAND flash business. Western Digital designs, manufactures, and sells HDDs used primarily for large-scale data storage in cloud data centers. The cloud end market now represents roughly 90% of revenue, driven by hyperscale customers — Amazon, Microsoft, Google, and Meta — buying high-capacity nearline HDDs in volume to support AI and cloud infrastructure buildout. Client (desktop/laptop HDDs) and Consumer (retail external storage) each account for roughly 5-7% of revenue. Western Digital sells directly to cloud providers and OEMs, and is vertically integrated, manufacturing its own recording heads and magnetic media across facilities in Asia. Revenue is driven by exabytes shipped and price per terabyte, with margin expansion coming primarily from mix shift toward higher-capacity drives. Western Digital's key proprietary technologies include ePMR and UltraSMR, which deliver roughly 20% more capacity per drive than standard SMR. The company's current volume product is a 32TB UltraSMR drive, with a 36TB next-generation drive expected in 2026 and heat-assisted magnetic recording (HAMR) drives targeting volume production in early 2027. Western Digital secures 52-week forward order visibility from major customers through long-term agreements, which supports supply discipline and pricing stability. The HDD industry is effectively a duopoly between Western Digital and Seagate in the high-capacity nearline market.