Using Application Services
Apple includes a bunch of application services in OS X, and individual applications can add their own (Opera and Skype both do, for example); other applications can use some of these as well (depending on how they are designed).
The application services available at any moment depend on which application (including the Finder) is running. To find out what services are available for a specific application, choose Services from your application's menu. For example, choose Finder⇒Services, Pages⇒Services, or Excel⇒Services.
The services are displayed contextually based—not only based on the application that is running but also based on what is selected. For example, when text is selected, Pages shows the Look Up in Dictionary, Make New Sticky Note, Send Selection, and Search in Google menu options. And both Numbers and Keynote show Look Up in Dictionary, Make New Sticky Note, Capture Full Screen, Capture Screen Region, Capture Timed Screen, Send Selection, and Search in Google, again only when text is selected.
Figure 12.4 shows the services available in the Finder when text is selected in the iBooks Author e-book creation program. Remember that the services displayed depend not just on the application in use but also what content is selected or active in that application.
OS X categorizes the available services based on the applications they are designed to work with, as Figure 12.4 shows. This keeps the services list uncluttered with irrelevant ...