Traditionally, the files on your computer are organized by their locations on your storage drive. Smart Folders change the organizing principle based on the search criteria you’ve chosen. These folders don’t give a hoot where the actual files that match your search criteria reside on the machine; the files stay put in their original locations. You are, in effect, working on aliases of (shortcuts to) those files.
What’s more, behind the scenes, Smart Folders are constantly on the prowl for new items that match your search criteria. In other words, they’re updated in real time.
To create a Smart Folder from an existing search, click that Save button in the Finder window Alternatively, in Finder, choose File→ New Smart Folder to create a new Smart Folder.
In the Finder window that appears, click the + to choose criteria for your Smart Folder, such as the kind of file that will be in your folder and the timeframe you’re looking at (Last opened date). From here on, your Smart Folder gets updated in real time.
When you click Save, you can specify a name and destination for your newly created Smart Folder. If you want, select the Add to Sidebar check box to easily find the Smart Folder you just created.
A premade Documents folder in your home folder contains, um, your documents. You can easily access the folder by clicking Documents in the sidebar. But you may want to create a simple Smart Folder containing all the documents you’ve worked on in the past seven days. Give it an original name. All your recent stuff is easily at your disposal. Your older documents will pass new arrivals on their way out.