Exiting apps?

I just noticed with mountain lion when you close an app (safari for example), it actually kills the app. With lion, it use to actually minimize the app and not totally kill it. Is there a way to get it back to that old function? I know most people would probably prefer this method, but i was so use to the old style, thanks.

edit: to make it more clear, even when i minimize an app now I cannot hit alt+tab and see it. I use to alt+tab to safari and then do the option release to re-open the app. Now I actually have to click on the icon on my dock.

 

nevermind....after doing some googling it is apparently a bug that restarting fixes.

 

No, I have had macs for a long time, but still use both. I meant cmd+Tab. For some reason, the apps were not showing when pressing cmd+Tab, but it is a known bug....i guess that is part of a new OS =/. Since restarting, I have not had the problem again, so hopefully it doesn't consistently do this.