> Can someone explain me the advantages and
> disadavantages in it?
well, the advantage is that if you have 2 web applications, you can logically separate them into separate wars so that you can reuse and it's more organized. disadvantage is that you cannot (easily) share sessions across wars. there are more advantages and disadvantages than just that, but that's what comes to mind.
> And also is it possible to have a seperate ear in a
> war ?
No.