In addition to the 'natural discovery' method of locating content in the Facebook Platform, the major discovery route for content is through the search functionality of the platform. The search capabilities available to us as developers through the Graph API are almost, if not exactly, the same as the search capabilities available to the user through the Facebook.com website.
As detailed in the online Facebook Developer Documentation, the available object types for searching are:
Publicly-available posts, such as those by a Facebook User, Application, Page, or Organization in their Profile Feed
People (Facebook Users)
Pages (Businesses, Organizations, and so on)
Facebook Events
Facebook Groups
Facebook Places, which can be retrieved by location as well as name
Facebook User Check-ins
News Feeds for a specific Facebook User
As you might expect, the search capabilities are flexible, allowing us to make searches by name and by type, and in the case of Facebook...