Spotlight isn’t just in that circle with a magnifying glass at the top of your screen. It’s also in the Finder where the old search was located in previous versions of OSX. When you search there, however, you get a little something extra with your search.
You’ll notice when you do a search in the right hand corner of the Finder window, there is a SAVE button.
If you click it, it saves your results in a folder in your sidebar, where you can re-access those files at any time…but even better than that. It’s a SMART folder. So from now on, when you add files to your system that match that search term, it will add them to that folder. Pretty sweet, huh?