Smartwatch is a small computer worn on a band around the wrist, resembling a wrist watch . A smartwatch enables the user to send and receive text messages . It may track the user’s location and measure the user’s movement and heart rate, among other features. Some smartwatches require the user to have a smartphone, through which the watch can access the internet . Other smartwatches can function without a smartphone connection. Many smartwatches work through the use of apps (applications), similar to smartphone apps.
Users generally interact with a smartwatch via a touch screen . They may also use voice commands, or buttons or other devices built into the watch’s case. A smartwatch may communicate with a smartphone or other devices wirelessly using a Bluetooth or Wi-Fi connection. Some smartwatches can directly access cellular data networks.
Many smartwatches are used to track physical fitness activity. A smartwatch may measure the user’s movements using such devices as accelerometers and gyroscopes . An accelerometer measures acceleration (changes in an object’s motion). A gyroscope measures changes in orientation. Some smartwatches can also measure changes in location using a Global Positioning System (GPS) receiver. A smartwatch may monitor the user’s heart rate by shining a light-emitting diode (LED) on the skin of the wrist. The amount of light reflected changes with the flow of blood through the wrist, enabling a light sensor to detect heart rate. All of this data can be stored and analyzed to study the wearer’s activity. A fitness tracking app may, for example, use such data to calculate and record the number of steps taken by the user, or to count the calories burned.
In the 1970’s, watchmakers such as Seiko and Casio began making watches that used simple computers to store information, function as calculators , and enable users to play games. Modern smartwatches started growing in popularity in the 2010’s.
