The Apple Watch Series 5 is a smartwatch designed by Apple Inc. The 44mm variant refers to the size of the case, and LTE (Long-Term Evolution) indicates cellular connectivity, allowing the watch to operate independently of a paired iPhone. Key features may include:

1. Always-On Retina Display: The Series 5 introduced an always-on display, allowing users to see the time and other information without having to raise their wrists.

2. LTE Connectivity: With LTE, the Apple Watch can make and receive calls, send messages, and stream music even when your iPhone is not nearby.

3. Health and Fitness Tracking: The Apple Watch is equipped with various sensors for tracking health and fitness metrics, including heart rate monitoring, ECG (electrocardiogram) capability, and GPS for accurate outdoor activity tracking.

4. ECG App: The electrocardiogram app allows users to take ECG readings directly from their wrists, providing valuable insights into heart health.

5. Built-in GPS: The GPS feature enables accurate distance and location tracking during outdoor activities like running or cycling.

6. Water Resistance: The watch is water-resistant, making it suitable for activities like swimming and tracking water-based workouts.

7. App Ecosystem: Users can access a wide range of apps from the App Store, including those for productivity, communication, and health.