The A - Z of wearable tech

All the wearable tech terms you need to know and a few you’ll wish you didn’t
Lifestyle photo for Fitbit Versa 3.
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If you're buying a smartwatch, fitness tracker or any wearable device, you're about to enter a new world of epic jargon. Wearables suffer from more tricky tech terms and future slang than your average gadget – and it's easy to be baffled.

This A-Z is designed to be a seriously helpful (but not always serious) resource for anyone new to wearable tech whether it's buying your first fitness tracker or picking up your first pair of smart glasses.

We'll continue to keep our wearable tech dictionary updated with the terms we think our worth adding to your wearable vocabulary.


accelerometer n. A device that measures acceleration/g-force, used in pedometers, phones, smartwatches, fitness trackers and even smart swimming goggles to more accurately count your movement. That could be steps, swim strokes or even running on a treadmill. Some trackers then add fancy algorithms using your height/weight/age to estimate calories burned from accelerometer and GPS data.

altimeter n. Even better for hikers, or anyone who works on the 22nd floor, an altimeter measures your altitude above a fixed point. Proper pals with the accelerometer, the elevation-tracking altimeter knows that not all steps are equal. This is a feature you want on a fitness tracker, smartwatch or sports watch if you want to track floors climbed or altitude when you're out climbing up mountains.

ambient computing n. Sounds crazy but actually you already know about it already. Think Siri and Alexa. Tech all around you, going about its business.

AMOLED n. Stands for Active Matrix Organic Light Emitting Diodes. It's a super bright display type found on smartwatches including ones made by Samsung, Fitbit and now even Garmin.

Android Wear n. The former name of Google's smartwatch operating system. Now called Wear OS and will soon just be called Wear. Unlike Apple's watchOS operating system, which only runs on the Apple Watch, Wear OS runs across smartwatches made from a host of brands including fashion brands like Michael Kors and tech outfits like Oppo, Mobvoi with its TicWatch range and soon Samsung. It offers notifications, access to the Google Assistant smart assistant and the Google Play Store to download apps.

atrial fibrillation n. Also known as aFib, this is a condition that means you have a quivering or irregular heartbeat. Erratic signals impact your heart's natural heartbeat, which can lead to a build up of blood in the upper chambers of the heart, which can lead to blood clots and, in turn, increasing the risk of heart attack and stroke. Smartwatches like theApple Watch and the Fitbit Sense have the sensor technology on board and necessary regulatory approval to help detect signs associated with atrial fibrillation.

augmented reality n. It's augmented reality when you can still see your living room through whatever is displayed on the smartglasses. If you're bumping into tables, it's virtual. AR has really hit the headlines with Pokemon Go, but as tech matures, there will be far more useful applications than that.


bioimpedance n. Usually followed by 'sensor'. Essentially refers to the measurement of body composition and water content by passing an electrical current through the body. It's real science - smart scales use bioimpedance to measure muscle mass vs fat - but the technique has also been used to make wilder, unproven claims such as measuring glucose levels.

bionic adj. The way we use it, the merging of biology (that's us) and electronics (that's the fun stuff) to give amputees robotic limbs and the rest of us, one day, superpowers.

Bluetooth n. Wireless tech using radio waves to move info about over short distances and, for now at least, what makes the wearable world go round. If it connects to your phone, chances are it uses Bluetooth. If you think you've never used it, find Bluetooth right there in settings usually under Wi-Fi.

bpm n. Beats per minute, of your heart that is. Useful to see how hard you're working during gym training or running and measured by more and more wearables. See heart rate training zones.



cadence n. Steps per minute while running, determined by height, weight, stride length and ability. The magic number for pros is considered to be 180, yours will probably be 160 - 170. In cycling, it's your pedalling rate.

calorie denial n. Someone who lies to MyFitnessPal or 'forgets' to act honestly towards any food tracking app is in denial of their calories. They have no respect for themselves. Or others.

crowdfund v. Historic usage: to throw cash at vapourware made by companies you've never heard of that you have a 9% chance of actually owning using sites such as Kickstarter or Indiegogo. Current usage: to throw cash at devices made by companies you've never heard of that you have a pretty good chance of wearing in 6-12 months time using sites such as Kickstarter and Indiegogo.


data n. How most health and fitness wearable tech makes itself useful - collecting data about your body or its performance. Aggregated and (sometimes) explained and analysed in device companion apps and all-in-one apps such as Apple Health, Google Health and Samsung Health. A problem with big potential.

Dick Tracy n. This guy. He solved comic strip crimes from the 1930s to the 1970s and beyond with help from his Two-Way Wrist Radio. Thanks to cellular smartwatches like the Apple Watch Series 6 - which even includes a walkie talkie feature - we can now do this.



early adopter n. The only person patient enough to buy, wear and use most wearable tech before late 2014. Owned a smartwatch in the mid 90s. Still has it somewhere if you're interested.

E Ink/e-paper n. OK, here goes - e-paper refers to any display tech that aims to look like paper: high contrast, easily visible in sunlight, low power, usually black and white. E Ink is one specific company making very good e-paper displays for the Amazon Kindle and even dropping them on hybrid smartwatches like the Skagen Jorn Hybrid HR. Phew, that was easier than we thought.

Electrodermal n. A method of measuring the electrical conductivity in the skin, which can be used to indicate emotional responses or stress on the body. Fitbit's Sense smartwatch is capable of tracking electrodermal activity to delve deeper into monitoring stress.

ECG n. Built into newer wearable devices like the Apple Watch Series 6 and Withings ScanWatch, an electrocardiogram is used to detect cardiac abnormalities. It does this by using electrodes on the skin to measure electrical activity produced by the heart.


Fast-charging n. Quite simply, the ability to drop your smartwatch or sports watch onto a charger and power it up in minutes. The Fitbit Sense and Versa 3 smartwatches include fast charging technology, while the Oppo Watch uses something called VOOC flash charging technology, which works in a similar fashion.


galvanic skin response n. Sweat much? This is the change in the amount of moisture on your skin and therefore how much it conducts electricity. Also known as skin conductance, it can tell clever wearable sensors how stressed or nervous you are. Like taking a constant lie detector test for fun.

glucose monitoring adj. The next frontier in wellness, there are now glucose monitoring wearables, that can read glucose levels, which has huge applications for health devices. The Apple Watch can support glucose monitors directly while Fitbit and Samsung are actively exploring bringing glucose monitoring features to their wearables.

GPS n. A device that has a Global Positioning System chip means it can determine its location on the earth's surface down to a couple of feet. Primarily this is used by running watches for accurate outdoor run-tracking, which remains the only true way to get reliable distances.



hypoallergenic adj. Shouldn't make your skin itch or get irritated but still might. Unregulated term, proceed with some caution.

hybrid smartwatch n. A watch which appears to be a standard analogue watch with hands, yet has hidden technology in the case. This is generally step tracking tech that syncs with your smartphone, but increasingly moving to notifications, expressed by vibrations and moving the watch's hands. There's some pretty great hybrid smartwatches you can slap onto your wrist now.

Harmony OS n. The operating system introduced by Huawei that will run on a host of devices including its latest smartwatches and debuted on the Huawei Watch 3. Unlike the LiteOS running its Huawei Watch GT series watches, Harmony brings an app store, a smart assistant and LTE to use the smartwatch untethered from your phone.

heart rate monitoring n. See optical heart rate.

heart rate variability n. The measurement of the time interval between heartbeats. Unlike measuring heart rate, which is about the average number of heart beats per minute, heart rate variability of HRV focuses on the small fluctuations of the heart. Watches from Garmin, Fitbit and Apple take these measurements for a variety of reasons including evaluating physical and mental stress and whether you're overtraining and should consider putting your feet up for a rest day.


IFTTT n. If This Then That. An app and web platform that lets you hook up two or more devices, apps or services to set up automatic actions.

Do say: IF I walk in my front door wearing my Apple Watch THEN my Philips Hue bulbs should throw me a light party to distract me from my crushing loneliness.

IPXX n. An official way of testing how water resistant, waterproof or dustproof a wearable is. The first number is dust, the second is water. Higher is better. X5 will do for casual use, X8 for swimmers.


(smart) jewellery n. Wearable devices that take the form of earrings, necklaces, rings, bracelets and brooches and connect to your self or smartphone in some way. Some buzz, some blink, some track. Smart rings are becoming a popular form factor to bringing those smarts to another part of the body.


Kinetic n. to produce movement and is a method that continues to be explored to solve one of the biggest flaws of smartwatches - battery life. Harvesting movement energy isn't new to the tech world but it's a method of powering watches that continues to be explored. An Apple Watch that can charge while you go for a quick 5k is definitely a future we want to be part of.


LTE n. The technology that enables wearable devices to have their own high-speed cellular connectivity, LTE is the same as 4G. Primarily seen on smartwatches that can operate untethered from a smartphone. It has featured on the Apple Watch, Samsung Galaxy Watch and Wear OS smartwatches like the Oppo Watch.

Lactate threshold n a fitness metric that sports watches from the likes of Garmin and Polar will dish out. It relates the level of exertion beyond which lies tiredness and pain. It usually strikes at upwards of 90% of your maximum heart rate. Run below threshold and you could have pushed harder, run above it and you will fade before the finish, so working out your level can be critical to race times.


Micro LED n. A superior type of display that's rumoured to be hitting smartwatches including a future Apple Watch, but has still to debut. It's superior to AMOLED because it has higher brightness and demands less power than the current popular screen technology.

MPU n. A low powered alternative processor which enables wearables to go about their sensing business without draining the battery of its juice before you've made it to the bus stop. The iPhone uses a motion co-processor (basically an MPU) to do its Health gubbins on the sly.


natural language processing n. The tech that will mean you'll be able to have a conversation with Siri/Google Assistant/Alexa without wanting to bash your smartwatch or smartphone's brains in. Essentially, what's needed for a personal, voice-activated assistant to understand and respond in natural, conversational language instead of stilted keywords.

NFC n. Near Field Communication. This tech has been around for ages but has finally taken off thanks to services like Apple Pay and Google Pay. Once it's switched on, a simple tap is required to pair devices or transfer info.

notifications n. An alert from your smartphone that's delivered to your wearable device. Smartwatches are all about delivering notifications of texts, messages and calls, and many fitness trackers ape the functionality.


open source adj. The geek way of saying “everyone come in, take what you want and build something cool because we can't, won't or are simply too awesome to care otherwise". Usually refers to software.

optical heart rate monitoring n. A way of measuring your pulse using LEDs to highlight the speed of blood flow through your capillaries. No chest strap required (though one of these is still more accurate, especially at higher bpms).



power management n. A feature on some devices that means they will power off or switch to a low power mode when it makes sense to do so. The dream.

PPI n. The amount of pixels per inch that make up your device's screen. The more pixels packed into the screen, the crisper the picture will be.


Qi n. If your gadget or wearable supports wireless charging, chances are it uses this standard. See 'W'.

quantified self n. The big trend of tracking ourselves - from the food we eat to the exercise we do to how happy we are. Also an honest-to-goodness movement, popular in the US.

Don't say: I can't bear to look at my quantified self in the mirror.


RFID n. Tiny wireless radio tags that can transmit info from, for instance, wearables. Also fan favourite for implanting in brave human bodies.


SDK n. A bunch of software development tools made available so that devs can build apps for your smartwatch etc. Anyone who is anyone in wearables has just released an SDK and is really excited about it.

Sleep apnea n. Sleep apnea is a sleep disorder where breathing is interrupted during sleep and could lead to experiencing tiredness, changes in mood and headaches when you wake up the next day. Wearables are starting to be capable of tracking those breathing disturbances by including an SpO2 sensor, which we'll get into below.

SpO2 n. An optical heart rate sensor that can detect the amount of oxygen in your blood - increasingly found on Fitbit and Garmin devices. Generally SpO2 tracking wearables do that monitoring at night but many devices also offer the ability to continuously to it too, dropping or highly variable blood oxygen levels can point to health conditions such as sleep apnea as described above.

SWOLF n. Scoring system, used by swimmers and featured on some Garmin watches. Add your lap time to the number of strokes taken to get your SWOLF score. Lower is, of course, better. And yes, the word is swim + golf.



tech neck n. slang Wrinkles that appear on the necks of smartphone addicts who spend too much time looking down. Creams actually exist for this condition but posture trackers, smart jewellery and smartglasses will also help keep our eyes and chins up.

Transflective n. Liquid crystal display technology favoured by Garmin and found on budget Amazfit smartwatches. It transmits and reflects light and is well suited to viewing in bright outdoor light and is kinder on battery life compared to AMOLED and other color display technologies.

Tizen n. The operating system developed and used by Samsung on its range of smartwatches, but will soon be swapped for Google's Wear. It's comparable to watchOS and Wear OS in terms of functionality, but suffers from a more limited app store and Samsung will be hoping the OS switch will improve that.


UI n. Stands for user interface and refers to the controls and graphics that you see and use to interact with the wearable tech OS usually via a touchscreen. Need to be big, bold and intuitive to stand a chance.


virtual assistant n. See ambient computing.

VO2 max n. A way to boast how fit you are. VO2 max measures the volume of oxygen you consume when exercising at your maximum capacity. As you get fitter, the amount of oxygen your body transfer will go up – making it the true barometer of your fitness.



watchOS n. Apple's smartwatch OS found on the Apple Watch. watchOS 8 is the latest version announced that will officially land on Watches soon.

wearable n./ adj. Finally! The meaning of life (if your life really IS wearable tech). We define a wearable as tech that connects to you in some way. Think of it this way - if there's no reason to wear it, it probably shouldn't be worn. We wouldn't buy, say, a solar charging jacket that takes all day to recharge our phone, we'd just pick up a cheap powerpack and stick it in our pocket for 20 minutes.

Wear OS n. Google's smartwatch operating system. Named Wear OS to better separate it from the Android brand, making it clear that its smartwatches work with both iPhones and Android phones.

wireless charging n. Uses an electromagnetic field to transfer energy from a mat or dock to a smartwatch or smartphone. The future. Though, for now, wired charging tends to still be quicker.


(heart rate training) zones n. Based on your bpm. Use a running watch, tracker or strap to make sure you are in the right one of zones when training for either recovery, fat burning or cardiovascular benefits. Athletic? Get your full rundown here. Total beginner? Get your heart rate zones for dummies here.

How we test

Michael Sawh


Michael Sawh has been covering the wearable tech industry since the very first Fitbit landed back in 2011. Previously the resident wearable tech expert at Trusted Reviews, he also marshaled the features section of

He also regularly contributed to T3 magazine when they needed someone to talk about fitness trackers, running watches, headphones, tablets, and phones.

Michael writes for GQ, Wired, Coach Mag, Metro, MSN, BBC Focus, Stuff, TechRadar and has made several appearances on the BBC Travel Show to talk all things tech. 

Michael is a lover of all things sports and fitness-tech related, clocking up over 15 marathons and has put in serious hours in the pool all in the name of testing every fitness wearable going. Expect to see him with a minimum of two wearables at any given time.

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