I don't recall the exact number, but you have to take a few steps before Garmin actually starts counting them. This prevents things like sitting up from your chair, moving a few feet to grab the TV remote and then having them count as steps. It might even have something to do with your stride distance set up in Garmin, but I don't know for sure. I personally think Garmin does steps better than anyone else because there are very few false step recordings. I had a Fitbit years ago that I absolutely hated. I drive a tower truck at work. Because of the suspension, I could drive a couple miles to my first worksite and the Fitbit would already have me at 10-12K steps. My Garmin doesn't register any in the same truck. I suspect you may be seeing something similar with Apple. If you believe the Apple count is closer to the actual step count, you may have a defective accelerometer in your Garmin.
