Spotlight in OS X is so much more than just a search engine for your Mac.

Spotlight helps you find anything on your Mac. It indexes the contents of your Mac's hard drive to make it easier to find documents, emails, apps, music, contacts, and other information. It can also help you find information on the web, perform equations, and more.

How to access and use Spotlight in OS X Yosemite

  1. Click on the Spotlight icon in the menu bar, or hold down the command key and press the space bar. The Spotlight search field will appear in the middle of your screen.
  2. Type in your search query. Spotlight will return results as you type.

If Spotlight isn't finding what you're looking for, you can adjust its search results to be optimized for what you need. You can also exclude specific locations of your hard disk, to prevent Spotlight from searching information you'd prefer to keep private.

How to customize Spotlight search results

  1. Click on the menu.
  2. Select System Preferences.
  3. Click on Spotlight.
  4. You can drag the categories to change the order results appear. You can also check and uncheck selected categories if you'd like to exclude them from Spotlight search results.
  5. To exclude certain folders or volumes on your Mac from Spotlight search, click on the Privacy tab, click on the + button and add the folder or volume you'd like you to exclude from search.

Spotlight Suggestions return search results from the Internet, iTunes, the App Store, movie showtimes, nearby locations, and other online information. Your Spotlight Suggestions query gets uploaded to Apple's servers.

If you're nervous about sharing information online either with Apple or with their search partners (currently, Microsoft's Bing search engine), Apple has a tech note that explains how it works. But if that still doesn't make you feel comfortable, you can turn off Spotlight Suggestions by unchecking Spotlight Suggestions and Bing Web searches in the Search Results tab of the Spotlight system preference pane.