Nap Power Nap feature may also reach Apple desktop computers

iMac with Power Nap feature

With Power Nap, your Mac keeps working even when it's at rest. It periodically updates Mail, Contacts, Calendar, Reminders, Notes, Share Photos, Search my Mac and Documents in the Cloud. When you connect your Mac to a power source, it downloads software updates and backups with Time Machine. While all of these updates take place, the system remains silent and the lights and fans are turned off so that nothing disturbs you. When your Mac is activated, it is ready to use.