Press Command (⌘) + Shift + 3 to capture the entire screen
Press Command (⌘) + Shift + 4 to capture a selected area (drag to select, release to capture)
Press Command (⌘) + Shift + 4, then press Spacebar to capture a specific window (click the window)
Press Command (⌘) + Shift + 5 to open the screenshot toolbar (choose options for screen, window, or selection, then capture)
Press Control + Command (⌘) + Shift + 3 to capture the entire screen to the clipboard
Press Control + Command (⌘) + Shift + 4 to capture a selected area to the clipboard
Press Control + Command (⌘) + Shift + 4, then Spacebar to capture a window to the clipboard
Press Control + Command (⌘) + Shift + 5, then choose Capture to copy to the clipboard