Why are there two different sleep states on a MacBook? It seems that there are two different sleep states on my MacBook:

Sleep State 1:


Invoked by: closing the lid or by the sleep timer.
Awaken by: touching the trackpad, clicking the trackpad, pressing a key, or opening the lid.


Sleep State 2:


Invoked by: Apple Menu > Sleep (or its keyboard shortcut).
Awaken by: touching the trackpad, clicking the trackpad, pressing a key, or opening the lid.


You'll notice that the main difference between the two is that in the first one you can simply touch the trackpad and the computer will wake up.

I have two questions:


Why are there two different sleep states?
Are there any other differences between them besides the one I mentioned?


I'm not sure if this is relevant or not, but I changed my MacBook's settings to cause Sleep to only Sleep and not the default 'Sleep and Hibernate'.
There are really three, sort of, but they're not exactly as you described:


Display sleep: The screen goes blank after a certain amount of time. You can wake up the screen by touching the trackpad or pressing a key.
Sleep: In this state, the computer goes to sleep: the hard drive stops spinning and the CPU uses much less (almost no) power. This can be invoked by closing the lid of the laptop, selecting Sleep from the Apple menu, or via a timer. You wake up the computer by opening the lid or pressing a key.
Hibernation: If the battery is almost dead, the laptop will hibernate to save power. This is similar to shutting down, except all the contents of RAM are dumped to the hard drive, which makes it much faster to start up (as well as starting the computer up into the previous state). You have to hit the laptop power key to wake the machine from hibernation.