System shortcuts

Shortcut Full name Description
⇧ ⌘ Q Shift Cmd Q Log out
ctrl ⏏ Ctrl Eject Restart/sleep/shutdown dialog
⌘ ctrl ⏏ Cmd Ctrl Eject Restart
⌥ ⌘ ctrl ⏏ Option Cmd Ctrl Eject Shutdown
⇧ ctrl ⏏ Shift Ctrl Eject Put displays to sleep
⌥ ⌘ ⏏ Option Cmd Eject Put computer to sleep

Key combinations for working with windows

Shortcut Full name Description
⌘ W Cmd W Close front-most window
⌥ ⌘ W Option Cmd W Close all windows of the front-most program
⌘ M Cmd M Minimize front-most window to Dock

Shortcut for capturing a screen shot

Shortcut Full name Description
⇧ ⌘ 3 Shift Cmd 3 Take a screen shot
⇧ ⌘ 4 Shift Cmd 4 Capture selection of the screen (choose with mouse)
⇧ ⌘ 4
then Space		 Shift Cmd 4
then Space		 Screen shot of a single window
(choose window by clicking it)

Key combinations for working with programs

Shortcut Full name Description
⌘ Q Cmd Q Quit program
⌘ H Cmd H Hide front-most program
⌥ ⌘ H Option Cmd H Hide all programs but the front-most
⌘ ⇥ Cmd Tab Switch applications (cycle forward)

Shortcuts for working with documents

Shortcut Full name Description
⌘ N Cmd N New document
⌘ O Cmd O Open document
⌘ S Cmd S Save document
⇧ ⌘ S Shift Cmd S Save As
⌘ P Cmd P Print
⌘ Z Cmd Z Undo previous command
⇧ ⌘ Z Shift Option Z Redo previous command

Key combination: Working with text

Shortcut Full name Description
⌘ A Cmd A Select all
⌘ X Cmd X Cut
⌘ C Cmd C Copy
⌘ V Cmd V Paste
⌘ F Cmd F Find
⌘ G Cmd G Find next occurrence
fn ← fn Backspace Forward delete (on MacBook, etc.)

Shortcuts for problems with Mac OS X

Shortcut Description
⌥ ⌘ Esc Open "Force Quit" dialog
⇧ ⌥ ⌘ Esc (hold 3 seconds) Force Quit front-most program
V during Startup* Show log during Start (Verbose Mode)
⇧ during Startup* Safe Boot: Load only essential kernel extensions
⌥ during Startup* Startup Manager: Choose boot volume
C during Startup* Boot from CD/DVD/USB drive
N during Startup* Boot from network (Netboot) server
T during Startup*
 		 Use Mac as "external Firewire hard drive" (target disk mode).
Useful for capturing data from another computer.
S during Startup* Boot in Single User Mode
⌥ ⌘ P R during Startup* (hold until 2x start chime) Reset PRAM / NVRAM

* Press key(s) as soon as the start chime sounds, then hold until the chosen function shows up.

Intel Mac boot process 

  • Power on - startup chime: During the Power-On Self Test the hardware on yor Macs motherboard is tested (i.e. processor, RAM, LAN + WLAN, Firewire, USB). If you see a slowly pulsing LED or hear beeps every five seconds, you have a RAM problem. If everything is okay, the startup chime is heard. 
  • Light grey display: Now the Mac flicks on its display and looks for the "Boot.efi" boot loader. It is stored on a hidden GUID partition on all bootable hard drives, the exact whereabouts are stored in the Macs PRAM by the "Start volume" preference pane or the Boot Camp assistant. If it weren't there, the Mac would first look at all other bootable drives (internal hard drives, DVD, USB, network). If it were unsuccessful, you'd then see either a circle with a slash or a "folder with a question mark".
  • Apple logo: The boot loader now loads the Darwin Linux, the MAC OS X basis, and the Apple logo appears. Kernel and kernel extensions (KEXT) are loaded, and they take over the next steps. 
  • Spinnig gear (or "spinning wheel") below the Apple logo: The launchd daemon starts all processes necessary for Mac OS X.
  • Blue screen: Now that launchd has started the WindowServer needed for the Graphical User Interface (GUI) your Mac starts to look  like a Mac.
  • Log-in window: Now that launchd has started the Loginwindow.app either the log-in screen is shown or the pre-defined used is being logged-in automatically.
  • Finder: After logging in the log-in items you set in your account preferences are loaded. If you experience problems, i.e. repeated software crashes of any of your log-in items, you can use Safe Start: Press and hold the Shift key immediately after clicking log-in or AFTER the spinning gear shows up (if you hit Shift too soon you will end in Safe Boot mode). Safe Start deactivates the user's log-in items.