An easy way to switch between different open applications on Mac OS X is by holding the command key and pressing Tab. But you may have noticed this switches only between open Applications. What if you have more then one open instance/window of the running application? How to you quickly switch between two open Word documents?
This is how:
To switch between two instances of the same application (between two Preview windows for example) try the “Command + `” combination. It’s the key right above the tab key on the mac keyboard. This allows you to switch between two windows of the same app, and works with most applications.
Another time saving shortcut is “Control + Tab” within a web browser. This allows you to quickly switch between open tabs. Works in Safari, Firefox, and Chrome.
A bit awkward at first, but a real time saver once you get the hang of it.