Calm down… There are no tabs in your Mac OS. All program windows just open and use the same upper menu bar. You can simply find out which window is active by checking this upper bar. You can switch between programs or program windows by only directly clicking them or selecting them from the dock because of the lack of tabs.
But this is Mac. Of course there is a simple trick to switch between applications. You can use Command (The button with apple)+Tab (as in PC). But if you want to do it in Mac way, press F9 of your MacBook. It will tile all the open windows on your screen. If you just want to see only the open windows of the same program, then just F10. Cool isn’t it??
By the way, it’s called as: Exposé
