Wearable technology encompasses a broad family of devices designed to be carried on the body or integrated into clothing and accessories, enabling continuous collection of physiological signals, movement data, environmental context, and behavioral patterns. At its core, a wearable is a compact sensor suite paired with a processing unit and a communication channel that links to a smartphone, cloud service, or dedicated app. The promise of these devices lies not in a single metric but in a holistic picture that combines heart rate, gait, sleep st...