Such devices may include features such as a camera, accelerometer, thermometer, altimeter, barometer, compass, chronograph, calculator, cell phone, touch screen, GPS navigation, Map display, graphical display, speaker, scheduler, watch, SDcards that are recognized as a mass storage device by a computer, and rechargeable battery. It may communicate with a wireless headset, heads-up display, insulin pump, microphone, modem, or other devices.
Some also have "sport watch" functionality with activity tracker features (also known as "fitness tracker") as seen in GPS watches made for Training, Diving, and Outdoor sports. Functions may include training programs (such as intervals), Lap times, speed display, GPS tracking unit, Route tracking, dive computer, heart rate monitor compatibility, Cadence sensor compatibility, and compatibility with sport transitions (as in triathlons).
Like other computers, a smartwatch may collect information from internal or external sensors. It