Redefine your funda of "How to crack interview?"

Recently I give interview in one MNC (Multinational company). After few initial general discussion, she ask me to clarify difference between standby database and dataguard. I surprise by this question at first instant because I accept more challenging and discussion about some problematic scenario. In reply of this question I give clarification like one given below:-

Dataguard is set of process(you can call it infrastrcutre/architecture provided by Oracle) to configure standby database in order to protect your database against disaster.

But,.... But she was not convince by my explanation and stick to her question and then she redefine her question and asked me in another way:- why we want dataguard if we configure standby manually.

I thought, she wants more detailed answer for her initial question, So I try and give it as mention below

In absence of dataguard you have to transfer archive redo log manually(or by some code written by you) from primary database to standby database and then you have to apply it on your standby database. This require lots of manual work and efforts. To overcome this Oracle has its own environment/architecture to complete this task automatically, what you need is, just configuration of environment, and then oracle take care of all this stuff.

 After this explanation, I found that still she was not happy by my explanation(not even 1% !!) though my explanation is correct, and she want something else. I don't know, what she was expecting as answer of her question. Still, I am wondering what are the other possible explanation that I miss at that time, Please, let me know if you have some better explanation :) 

Moral of the story:- It is not important what is wrong and what is right during interview process, the important thing is, you should have answer what your interviewer has in her mind (No maters, wrong or right).