Switch between open apps with the keyboard

Hold ⌘ and press Tab. A row of icons appears; keep ⌘ down and tap Tab to move along it, then let go to switch. Adding ⇧ walks backwards.

The important difference from Windows: this switches apps, not windows. If Safari has four windows open, it counts once. That is why it sometimes feels like it is skipping something — the window you want is behind another window of the same app.

The companion shortcut solves that: ⌘ + ` cycles through the windows of whichever app you are already in. Together, ⌘ + Tab gets you to the app and ⌘ + ` gets you to the right window.

Only apps that are running appear in the list, and an app with no open windows still counts — remember that closing the last window usually leaves the app running.