This document discusses object-oriented programming (OOPs) principles and how they are implemented in Objective-C. It explains that OOPs aims to emulate the human brain through abstraction, encapsulation, and other principles. It provides examples of key OOPs concepts in Objective-C like classes and objects, inheritance where subclasses inherit from superclasses, encapsulation which hides complexity, and polymorphism which allows one interface to work for multiple classes through dynamic binding and message passing. The document demonstrates how these OOPs features are exhibited in Objective-C code.