Ok, so now that you know what Facebook is, you probably are asking how can I build a Delphi application to allow me and my friends to "connect" to Facebook more easily :)
You should be looking at the Facebook for Developers - allowing developers, for example, to build "Facebook apps" - web applications that are loaded in the context of Facebook.
Given that Delphi is a Win32 development environment, let's see if there are some libraries to help you build some Facebook apps (or anything Facebook-aware).
- Facebook API in Delphi - a discussion on Embarcadero Forums including some Delphi code you can use as a starting point to explore possibilities.
- Facebook Client Library for VB.NET. Ok, this is for Visual Basic and is .Net. The basic idea during development of this library was to make it as easy as possible to connect to and manipulate the Facebook API from either desktop or web-based applications. Note that you can use a .Net assembly from Delphi Win32
More at http://delphi.about.com/b/2011/07/19/facebook-and-delphi-facebook-api-for-delphi.htm