Messages consist of the integrity of the target object, the name of the requested operation, and any other action needed to perform the function. A class defines all the attributes, which an object can have and methods, which represents the functionality of the object.
Classes: A class is a generalized description of an object.Every entity has some attributes associated with it and has some methods to perform on the attributes. For example, person, banks, company, and users are considered as objects. Objects: All entities involved in the solution design are known as objects.The different terms related to object design are: Classes may inherit features from the superclass. In other words, each object is a member of some class. Objects have their internal data which represent their state. The tasks defined for one purpose cannot refer or change data of other objects. For example, in a Library Automation Software, each library representative may be a separate object with its data and functions to operate on these data. The state is distributed among the objects, and each object handles its state data. In the object-oriented design method, the system is viewed as a collection of objects (i.e., entities).
