Global Handheld Computers Market Size, Share & Demand Report By Product Type (Rugged, Enterprise Non-Rugged, Wearable Handheld Computers), By Operating System (Android, Windows, Linux, Proprietary OS), By End-Use Industry (Logistics & Warehousing, Retail, Manufacturing, Healthcare, Government & Public Safety, Transportation, Energy & Utilities), By Connectivity (Wi-Fi, Wi-Fi + Cellular, IoT-Enabled Devices), By Region & Segment Forecasts, 2026–2031