In the older days and still now we have buttons where one way is off and the other way is on, its mechanically built to connect or disconnect an electric path physically.
On modern devices like laptops the power buttons work differently. Push once, it's on, Push again, it won't turn off and will go to sleep mode instead. Keep the same button pressed for around 3 seconds and the laptop shuts down as if the power was literally cut off.
These buttons surely have a more complex mechanism than just connecting or disconnecting a wire.
Does anyone know how those circuits have been designed? I am quite curious as to how these power switches work.