Wearable computers are portable computers that can be worn on the body through clothing or accessories. They have human interface systems, networks, and display systems. The user interface must be constantly available without requiring constant attention while allowing communication. Network connections can be through wireless technologies or infrared. Input can be through speech recognition, handwriting, gestures, or thumb typing. Displays include head mounted displays or earpieces. Examples of wearable technologies are smart shirts for health monitoring, smart watches, smart glasses, and smart rings. Potential applications include health monitoring, military uses, smartphones, electronic textiles, gaming, and fashion.