the.com/sleep states
the OS pretending to be dead without actually dying, to save you from a low-battery funeral.
means the power-saving modes a computer uses between fully on and fully off, trading wake-up speed for energy savings.
from formalized in the mid-1990s ACPI spec (Intel, Microsoft, Toshiba), which numbered them S0 through S5 so every OS and BIOS could agree on what dead meant.
s3 sleepram stays powered, everything else shuts off
s4 hibernateram dumped to disk, power fully cut
s0 modern standbyphones stay half-awake checking notifications
resume timethe real tradeoff, not just battery life