Object-oriented design
Object-Oriented Design (OOD) is a way for the designer of a computer program to specify what a computer program will do, using the way that people think and not using the way that computers think.  People think in terms of classes and objects.  For example, fruit is a class, and there are different kinds of fruits such as bananas and pineapples.  If a computer program designer were specifying to a computer programmer how to create a computer program to manage the fruits in a supermarket, then he or she would specify the program in terms of classes and objects which is how people think.