NSBundle class is a subclass of NSObject and available from version iOS 2.0. Its object represents a location in the file system that groups code and resources which can be used by any program.

Means whenever we create any application the data of application is stored in the "application bundle" by the system - which can include resources like strings, images, videos, icons, and so on. So if we want to access (use) those resources from our application then it is necessary to know about NSBundle class.