To turn off your Apple Watch, you can follow these steps:
1. Press and hold the side button (located below the Digital Crown) until you see the Power Off slider appear on the screen.
2. Swipe the Power Off slider from left to right using your finger.
3. Wait for your Apple Watch to power off completely. You may need to wait a few moments for the process to complete.
Once your Apple Watch is powered off, the screen will go black, and it will no longer be active until you turn it back on again.