A smartwatch is a computerized bracelet. While early models can perform basic tasks, such as calculations, translations, and game-playing, 2010s smartwatches are effectively wearable computers. Many run mobile apps, using a mobile operating system. Some smartwatches function as portable media players, with FM radio and playback of digital audio and video files via a Bluetooth or USB headset. Some models, also called 'watch phones' (or vice versa), feature full smartphone capability, and have complete functionality of a typical smartphone.[1][2][3]
While internal hardware varies, most have an electronic visual display, either backlit LCD or OLED.[4] Some use transflective or electronic paper, to consume less power. Most have a rechargeable battery and many have a touchscreen. Peripheral devices may include digital cameras, thermometers, accelerometers, altimeters, barometers, compasses, GPS receivers, tiny speakers, and SD card (that are recognized as a storage device by a computer).
Software may include digital maps, schedulers and personal organizers, calculators, and various kinds of watch faces. The watch may communicate with external devices such as sensors, wireless headsets, or a heads-up display. Like other computers, a smartwatch may collect information from internal or external sensors and it may control, or retrieve data from, other instruments or computers. It may support wireless technologies like Bluetooth, Wi-Fi, and GPS. For many purposes, a "watch computer" serves as a front end for a remote system such as a smartphone, communicating with the smartphone using various wireless technologies. Smartwatches are advancing, especially their design, battery capacity, and health related applications.
