Why does my watch say im asleep when im not?

My watch says i slept from 21.15 last night, but i was awake and actually using my iphone the whole time until 22.45, which is when i put sleep focus on and went to sleep.

Is the sleep app not all that accurate?

My watch says i slept from 21.15 last night, but i was awake and actually using my iphone the whole time until 22.45, which is when i put sleep focus on and went to sleep.

Is the sleep app not all that accurate?