In many of our projects we see that a header file called #import <
is imported by default today we will have a look at this header file.
The above line means that you will be using some of the classes from the Foundation Framework, The objective C foundation framework is a set of classes that are provided to ease the developers in developing the applications.
The foundation framework was developed by the organization called as the NEXT computers as a part of their NEXTStep as part of Next step environment. Whne Next was taken over by Apple Inc then the developers at Apple used Foundation framework as a part of the development for MAC OS X and after the success of MAC OS X they used it for the development for iPhone development kit.
Since the foundation framework took birth at NEXT all the classes which are present and in the foundation framework begin with the letters "NS".
Just recall our string and array demos you have seen that we have used NSObject, NSString,NSArray NSMutableArray all these classes are coming from the foundation framework.
In order to know more about the foundation framework you can click here