1. Write Benefits of Reusable objects and code?
• Increases productivity
• Decreases maintenance
• Increases modularity
• Maintains standards
• Improves application performance

2. What is property class?
A property class is a named object that contains a list of properties and their settings.

3. Why use property classes?
Use property classes to:
• Increase productivity by setting standard or frequently used values for common properties and associating them with several Forms Builder objects.
• Improve network performance by increasing the efficiency of message diffing.

4. What is an Inherited property?
An inherited property is one that takes its value from the property class that you associated with the object. An inherited property is displayed with an arrow to the left of the property name.

5. What is a Variant property?
A variant property is one whose value has been modified from the inherited value that comes from the property class associated with the object.

6. What are object groups?
An object group is a logical container for a set of Forms Builder objects.

7. Why use object groups?
• Package related objects for copying or sub classing in another module
• Bundle numerous objects into higher-level building blocks that you can use again in another application.

8. What are object libraries?
Object libraries are convenient containers of objects for reuse. They simplify reuse in complex environments, and they support corporate, project, and personal standards.

9. Why object libraries Instead of object groups?
• Object libraries are external to the form, so are easily shared among form modules.
• Object libraries can contain individual items (for example, iconic buttons). The smallest unit accepted in an object group is a block.
• Object libraries accept PL/SQL program units.
• If you change an object in an object library, all forms that contain the sub-classed object reflect the change.

10. Write the benefits of the object library?
• Simplifies the sharing and reuse of objects
•Provides control and enforcement of standards
•Promotes increased network performance
•Eliminates the need to maintain multiple referenced forms

11. What are smart-classes?
A Smart-class is a special member of an object library. It can be used to easily subclass existing objects in a form using the Smart Class option from the shortcut menu.

12. What are PL/SQL libraries?
A Library is a collection of PL/SQL program units that can include procedures, functions, and packages.