I doubt anyone will answer all that. I may be wrong, but most people here won't answer what look like interview/homework questions (i.e. do your work for you). What I can suggest is you start to look for you answers by doing the Java/J2EE etc. tutorials on Sun.
Sabdhya- That sure is a lot of questions to ask someone to research and find the answers for, when its perfectly possible for you to do the work on your own. Also, realize that here at the JavaRanch, we're more than happy to help you with your homework, but we won't do it for you.
I'm going to move this to the "EJB and other J2EE technologies", seeing as though most of the questions fall into that category.
if you ask so much rather easy question - i believe you will like easy-to-read books "Head First Java" and "Head First EJB" you will find there all answers
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You ought to ventilate your mind and let the cobwebs out of it. Use this cup to catch the tiny ads: