Smartwatch
A smartwatch is a wearable device that carries notifications to your wrist and records data such as steps, heart rate and sleep. It works as an extension of the phone.
| In brief | A wearable device worn on the wrist that shows notifications and records data such as steps, heart rate and sleep. |
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| What it does |
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| What to look for |
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| Privacy note | Health data such as heart rate and sleep may be held on the manufacturer's servers; it is worth reviewing data sharing permissions in the account settings and switching off any that are not needed. |
| Limits | Measurements are not at the precision of a medical device; they suit the following of trends and do not take the place of diagnosis or treatment decisions. |
What is it for?
A smartwatch has two main roles. The first is communication: it lets you see notifications and answer calls and messages quickly without taking the phone out of your pocket. The second is tracking: its sensors record data such as step count, heart rate, sleep duration and exercise. Many models add functions such as payment, navigation, music control and a voice assistant.
What to look at when buying
The first measure is compatibility: some watches are fully functional only with particular phone brands, and choosing the watch to match your phone prevents disappointment. Battery life ranges from a day to several weeks between models and may be decisive depending on your habits. The screen type (whether or not it stays always on), the level of water resistance, how well the strap and case size suit your wrist, and the application ecosystem are the other important headings.
How reliable are the measurements?
Measurements taken at the wrist with an optical sensor are useful in practice as a guide, but they are not at the precision of a medical device. Heart rate readings can drift during vigorous movement; sleep stage estimates are approximate values; calorie estimates carry a wide margin of error. This data is a useful starting point for following trends; it is not a diagnostic tool. If a warning from your watch is causing you anxiety, the right address is not the device but a healthcare provider.
Related terms: Smartphone, Synchronisation, Cloud Storage