, if I don't shutdown windows 10 but just press the off button? Then it flashes…
If it flashes, it will likely be in sleep mode.
You can set exactly what happens when you press the switch in the system settings.
Control Panel → Power Options → "Choose what to do when you press power buttons"
So mine always goes into energy saving mode.
If you press the power button for a long time, it goes off.
For me, it's always about cooling the CPU and GPU.
Then he is in standby mode and a lot is switched off. The screen, the hard drive, etc. But some things are still there, e.g. The main memory, the keyboard, the touchpad. So the laptop uses electricity, but much less.