Anything that can be seen or touched is an object. Objects are everywhere around you. They may represent a book, your computer, a place, a person or any item that the program has to deal with.
Objects are often used in object oriented programming. Objects are basic elements in an object-oriented system. They are also known as class instances, class objects or instance objects.
During execution of program, the objects interact by passing messages to one another. A collection of objects is called a class.