Understanding the Facebook SDK
Facebook provides a Software Development Kit (SDK) for using the Facebook APIs in various platforms and languages. It has a wealth of information, sample codes, and "How-tos" to help you get started quickly with integrating Facebook into your application.
Note
All this information is available at https://developers.facebook.com/.
Since we will be building a web application, we would be more interested in the JavaScript SDK available at https://developers.facebook.com/docs/web/.
The Social Graph
The Social Graph is a mapping of different people and how they are related to each other within a network. Facebook uses this term to refer to the Facebook platform, which was introduced in May 2007. Within the Facebook Social Graph context, every person, page, photo, or comment is a node that is connected to each other with the relations they share.
The Graph API
The Graph API is the primary way of interfacing with Facebook's Social Graph. The Graph API is...