• 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.

Your answer should be relevant to the job for which you are being interviews. Do not start going into your personal life. Keep your self-introduction PROFESSIONAL.

A person is defined in three ways: (1) who he is right now, (2) what he has done in the past, and (3) what he will become in the future.

So, here is how you answer: (1) I am a [the job title for which you are applying or something very close.] (2) I have [how many years of experience] in [what field, what subject]. (3) I want to be [a job title that is a couple or a few levels above the current position for which you are applying in 5 to 10 years.]

Close your answer with an affirmative question: "Is there anything else you want to know?"

Here are more suggestions for answering this very common interview question.

• You should be very straight forward and honest in replying to this question. The interviewer wants to check if what you have mentioned in your resume is correct or not.

• I would answer the question based on who is interviewing me? If it's a sales manager/Technical Manager/Human resources manager? Depending on the person's field I'll have to mend the answer to please him...I feel that everyone's goals are different...so anlayse that and then answer.

• Answer this question with your 30 second "elevator speach" about yourself. The standard format for this speech is... "I am a (BLANK), who does (WHAT)." In my case... I am a PROJECT MANAGER, who PROVIDES QUALITY MANAGEMENT SOLUTIONS, Blah, Blah, Blah. (you get the idea).

• The Answer can Start like this: "I have 10 years' sales rep experience, working in a variety of industries, from retail to advertising. For the past two years I have been working in the food industry. In addition to my successful sales techniques, I have a great record for forming long-standing relationships with customers. I'm a team player who thrives on challenge."

• Let me share what my recruiting office tells its candidates as they head out for that crucial face-to-face interview. When asked to "tell me about yourself," say, "I will gladly answer that question, but may I first ask you a question? (They ALWAYS say yes) So that I may better focus my answer, what are the issues you want me to address should you hire me? Once they share with you what they need to have you do, then proceed to address how your training, education, skills, and experience can best resolve these issues. By answering in this fashion, you have proven that you know how to focus ... and that you have what's needed to fix the issues they need to have fixed. It's always a winner ... and beats the heck out of, "Well, let's see, I was born on a small farm in Idaho ..."

• I am a self-starter dedicated, hard-working person who works well with other, punctual, detail oriented a team player, great organizational and interpersonal skills.