Cocoa Framework in iPhone

Cocoa is an application environment for both the Mac OS X operating system and iOS, the operating system used on Multi-Touch devices such as iPhone, iPad, and iPod touch. It consists of a suite of object-oriented software libraries, a run-time system, and an integrated development environment.

snap1.png

Cocoa consists of the Foundation Kit, Application Kit, and Core Data frameworks, as included by Cocoa.h header file, as well as the libraries and frameworks included by those, such as the C standard library and the Objective-C run-time itself.
Cocoa applications are typically developed using the development tools provided by Apple, specifically Xcode and Interface Builder, using the Objective-C language.

snap2.png