Object-oriented design is the process of planning a system of interacting objects for the purpose of solving a software problem.
An object contains encapsulated data and procedures grouped together to represent an entity.
The object interface is also defined. An object-oriented program is described by the interaction of these objects.
Object-oriented design is the discipline of defining the objects and their interactions to solve a problem that was identified and documented during object-oriented analysis.
What follows is a description of the class-based subset of object-oriented design, which does not include object prototype-based approaches where objects are not typically obtained by instancing classes but by cloning other (prototype) objects.