To know which Apple Watch you have, follow these steps:

1. On your paired iPhone, open the Apple Watch app.
2. Go to the "My Watch" tab, then tap "General."
3. Tap "About."
4. Look for the "Model Name" to see the series of your Apple Watch. If it’s not shown, find the "Model Number" and tap it to reveal a code starting with "A."
5. Use this model number to identify your Apple Watch series by comparing it to a model number list, which corresponds to various Apple Watch generations.

Alternatively, you can check the back of your Apple Watch case for the model number or serial number. You can also check the Apple Check Coverage page online by entering your watch's serial number to get detailed model info. Would you need the model number list for comparison or instructions on how to physically find the model number on your watch? This will help identify the exact model from Series 1 to Series 10, Apple Watch SE, or Apple Watch Ultra models.