A bundle is a directory of resources that may be used by an application. A resource can be any kind of file: images, sounds, and NIB files. Bundles can also contain compiled code. The class NSBundle is a very elegant way of dealing with bundles.
Your application is a bundle. In Finder, an application looks to the user like any other file, but it is really a directory filled with NIB files, compiled code, and other resources. We call this directory the main bundle of the application.
To get the main bundle of an application, use the following code:
let bundle = NSBundle.mainBundle()
This is the most commonly used bundle. If you need to access resources in another bundle, however, ...