Sleep modes in OS X are designed to save power by shutting down unnecessary and power-hungry system components; however, there may be times after an update or other configuration change when the system hangs or otherwise malfunctions after being set to sleep.
OS X has two main sleep modes. The first is standard sleep, in which the system keeps the contents of its memory active by providing power only to the RAM chips. This allows quick wake-up times but also draws a touch more power as it requires uninterrupted power to maintain RAM contents. The second mode is hibernation, in … Read more