ADF stands for 'Applications Development Framework'
Oracle Application Development Framework (Oracle ADF) is an innovative, Java EE development framework available from Oracle and directly supported and enabled by evelopment environment, Oracle JDeveloper 11g
Oracle ADF simplifies Java EE development by minimizing the need to write code that implements the application‘s infrastructure allowing the developers to focus on the features of the actual application.
Oracle ADF is also focused on the development experience to provide a visual and declarative approach to Java EE development through
the Oracle JDeveloper 11g development tool.
Oracle ADF Provides end-to-end infrastructure solutions for O/R Mapping, persistence, caching, controller, binding, UI framework
Oracle ADF is an easy way to use them via Visual editors, Property editors, dialogs etc
What’s the Role of ADF in the world of Oracle
- The development framework for Fusion Applications
- The framework at the base of WebCenter
- The UI for SOA and BPM Suite
- Human workflows
- Used in other Oracle products like EM, Siebel and more
What is ADF Framework?
Is MVC pattern , used mostly for:
- Object/Relational mapping
- Data Persistence
- Reusable Controller Layer
- Rich Web User Interface Framework
- Data Binding To UI
This can be best Understood as:
Career future of Oracle ADF
ADF is core in Oracle Fusion Architecture and its growing fast both in Fusion Middleware and Applications, so lots of professional opportunities in the following years. Growth means Opps !
A good move in this skill set for those who worked in Java based technology.
Key Resource book/guide on ADF 11g.
A friend of mine extensively works in ADF technology mention sometime back, ADF is best learnt by samples.
If you want to learn concepts, read any of the books mentioned below.
- This one is great for ADF newbies:
- This one covers ADF Business Components in-depth:
- And this one covers the ADF Faces Rich Client components in-depth:
- Oracle Documentation
You can Check out these two free e Courses from Oracle.
- Part 1:http://download.oracle.com/tutorials/jtcd3/ecourse_adf_part1/html/temp_frameset/index.htm 
- Part 2:http://download.oracle.com/tutorials/jtcd3/ecourse_adf_part2/html/temp_frameset/index.htm 
To learn coding in ADF the Insider Series is very good
Conclusion – ADF is a key Oracle technology