system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How come my mac can go into sleep mode for what seems forever, but my PC laptop only sleeps for a few hours before dying?
gpt
So, your Windows laptop has two energy saving modes: sleep and hibernation. In sleep mode, everything is turned off except for power to the memory. In hibernation mode, the memory is written to disk and then everything powers off.

In Windows sleep mode, it lasts only as long as there is power available to it, either by being plugged in, or the battery. When the power is gone, what's in RAM is lost, and sleep mode is over. It's just turned off. Hibernation, on the other hand, can be indefinite.

The nice thing about sleep mode is that it's very fast to recover from; the laptop just has to power up the hard drive and monitor and all that. Hibernation takes longer because it has to reload the RAM from the hard drive.

Macs don't have two modes like this. They have one, and it's called sleep. And it's kind of a hybrid between the two. Like hibernation mode, the Mac writes the contents of RAM to disk. But, then it keeps power to the memory.

The result of this is that it has the near-instant startup time of sleep mode, **and** has the longevity of hibernation. If the power to the RAM runs out, then the Mac will simply reload it from disk. It's like automatically failing from sleep to hibernation mode.

The downside of this is just a little more time writing the memory to disk once the Mac goes to sleep, but it does this after you close the lid, so really, it doesn't have any impact to the user. It's really a better way to do it.

**TL;DR - It's a matter of terminology, and Apple combined two energy saving routines into one superior one.**