The Gear S3 also offers a dual-core Exynos 7270 processor, 768MB of RAM, and 4GB of storage. The watch also features sensors such as GPS, NFC, and even optional LTE. The standout features, though, include Samsung Pay (on any smartphone) and the rotating bezel. The Gear S3 is a pretty big watch, though, coming in at 12.9mm thick with a 46mm diameter.
They include a heart rate monitor, pedometer and altimeter to track steps taken and stairs climbed and often a GPS chip to record your distance covered. They will sync with your smartphone to give you a suite of tools to monitor your exercise progress. Many of them will offer notifications of incoming phone calls, text and email alerts as well. But they are designed with fitness tracking in mind. If you are happy using your smartphone for your day to day messaging, calendar, apps and music, a fitness tracker will suffice.
Bottom line: If health and fitness tracking is your priority, opt for a dedicated fitness tracker that gives you basic time and date information but includes the essentials of health tracking - accelerometer and altimeter, heart rate monitor and GPS chip to track distance and location. Carefully consider your exercise habits to match them to the right fitness tracker.
Waterproof to 165 feet and tested to military standards for durability, it includes features like a digital compass, altimeter, and barometer that you won’t find in most other smartwatches, as well as more standard tools such as GPS. The WSD-F20 can also function as a flashlight — handy in an emergency — and lets you download maps for offline navigation when you’re far from the nearest cell signal.
The top smartwatches that debuted at the 2017 Consumer Electronics Show included the Casio WSD-F20, Misfit Wearables Vapor and the Garmin Fenix 5 series. Apple released on September 22, 2017 their Apple Watch Series 3 model which offers built in LTE cellular connectivity allowing phone calls, messaging and data without relying on a nearby smartphone connection. 
Unfortunately, you won't be able to respond to alerts (like messages and emails) from the Charge 3. That's a feature sequestered to smartwatches, but you can see most of the content of an alert on the device's screen. Considering how narrow the device's screen is, reading through a long email won't be the most comfortable experience. But at least that message will be glanceable on your wrist, as will news headlines, text messages, and other alerts as well.
Samsung treads between smartwatch and fitness tracker, also packing in a heart rate sensor along with that GPS and its much-improved Samsung Health software. There's also the option of LTE (coming soon), if you wish for an untethered connection, with a standalone speaker for taking calls on the watch. It's now waterproof, too, adding swim tracking skills that are on par with the Watch Series 4.
Google confirmed to Tom's Guide that the company won't be releasing its own Wear OS smartwatch this year. The news comes after months of rumors that a Google-branded Pixel Watch running on Qualcomm's latest processor would be launched at Google's October hardware event. Instead, Google plans to focus on adding features to Wear OS on the software side and support the companies who are currently making Android smartwatches. Google's hardware event is Oct. 9.