What Exactly Is an Object?
Objects are the building blocks of an OO program. A program that uses OO technology is basically a collection of objects. To illustrate, let's consider that a corporate system contains objects that represent employees of that company. Each of these objects is made up of the data and behavior described in the following sections.
The data stored within an object represents the state of the object. In OO programming terminology, this data is called attributes. In our example, as shown in Figure 1.6, employee attributes could be Social Security numbers, date of birth, gender, phone number, and so on. The attributes contain the information that differentiates between the various objects, in this case the employees. ...