Apple Watch Series 4 review: specs and price

Dustproof/water resistant at depth equal to or greater than 1 meter.

Resistance to sweat makes it ideal for use while doing sports.

You can operate the device easily, by pressing the screen with your fingers.

The device has an electronic display to present information to the user.

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A heart rate monitor can help show your fitness levels, enabling you to calculate a suitable intensity of exercise.

GPS enables global positioning, useful in map, geo-tagging or navigation apps.

An accelerometer is a sensor used to measure the linear acceleration of a device. A common application is detecting when a device changes between vertical and horizontal positions.

A compass is useful in games, map and navigation software.

This measures barometric air pressure. It can predict weather changes, for example a sudden drop in air pressure could mean a storm is coming. When calibrated correctly it can be used to determine altitude, which helps GPS devices to lock on quicker and with greater accuracy.

A gyroscope is a sensor that tracks the orientation of a device, more specifically by measuring the angular rotational velocity. Initially, they were built using a spinning rotor to detect changes in orientation, like twisting or rotation.

It tracks how far you travel.

It tracks how many steps you take throughout the day, allowing you to see how active you have been.

Your activity data is analysed to give you reports, available to view through the app or website. This allows you to see how active you have been and to help you make improvements.

Measuring pace shows how much time it takes to travel one kilometer or one mile. For example, in running, a 4 minute kilometer would be a very good pace.

This is useful if you are on a strict training diet or if you are trying to lose weight. It can also help to boost your motivation.

It can track your sleep, such as how long you sleep for and the quality.

The device syncs all of your data wirelessly, without the need for cables.

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Bluetooth is a wireless technology that allows you to easily transfer data between different devices, such as smartphones, tablets and computers.

The device can connect to WiFi.

The device automatically syncs your data when in range of your computer or smartphone.

NFC (near field communication) allows a device to perform simple wireless transactions.

An indicator shows you when the device has low battery.

The battery can be recharged and used over again.

There is less chance that you will run out of battery during an adventure.

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The manufacturer offers a branded wireless charging kit. To charge the device, you simply put it down on its charging base.

If you get a notification such as a call or message, the device will vibrate on your wrist or make a noise to alert you.

The device has a feature that allows you to find your smartphone if you have misplaced it.

The device alerts you to incoming calls on your smartphone, and allows you extra control such as muting or rejecting the call.

With a stopwatch you can time yourself.

The device has a speaker and microphone that allow you to answer calls made to your smartphone.

It allows you to share information to popular social networks.