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.
Samsung's Galaxy Watch, a Tizen OS watch (starting at $329), is our favorite smartwatch for Android users. In addition to up to four days of battery life and a great design, the Galaxy Watch offers built-in GPS, heart rate sensor, water-resistance, Samsung Pay support, plus a nifty rotating bezel for navigating the interface. You can also download music from Spotify to the watch for offline listening. However, you get far fewer apps than you would with a Wear OS watch.