One reason interviewers ask this question is to see if you're settling for this position, using it merely as a stopover until something better comes along. Or they could be trying to gauge your level of ambition.

If you're too specific, i.e., naming the promotions you someday hope to win, you'll sound presumptuous.  If you're too vague, you'll seem rudderless.

BEST ANSWER:   Reassure your interviewer that you're looking to make a long-term commitment.that this position entails exactly what you're looking to do and what you do extremely well.  As for your future, you believe that if you perform each job at hand with excellence, future opportunities will take care of themselves.

Example:  "I am definitely interested in making a long-term commitment to my next position.  Judging by what you've told me about this position, it's exactly what I'm looking for and what I am very well qualified to do.  In terms of my future career path, I'm confident that if I do my work with excellence, opportunities will inevitable open up for me.  It's always been that way in my career, and I'm confident I'll have similar opportunities here."

• Presentation Layer
• Business Logic Layer
• Data Access Layer

In most of the cases the data entered by the end user needs some kind of validation or further processing. This is the responsibility of Business Logic Layer.

Finally, your application data needs to be stored and retrieved in some data store (RDBMS, XML etc.). This task is handled by Data Access Layer.

In short, the process works like this:

• User requests for some application data.
• The data access layer retrieves the data and is forwarded to the presentation layer via business logic layer. Sometimes data access layer gives this data directly to presentation layer.
• Presentation layer receives the data to be displayed via business logic layer.
• The user changes the data and initiates the appropriate action (such as insert, or update).
• The business logic layer validates the data submitted by the user.
• If the data is valid it is handed over to data access layer for updating into the database.

• The applications gets divided in logically isolated pieces reducing tight coupling between the UI, business processes and database.
• Change in the underlying database and data access methods do not have any effect on the presentation layer or client application.
• Client application no longer has SQL statements embedded in it. This makes it de-coupled from rest of the application.
• Table and column names can be effectively eliminated from the client-side code.
• The client application is unaware from where data comes (location transparency).
• It becomes easier to modify or extend your application, without breaking or recompiling the client-side code.