Beginner: Action Forward & Global Forward

[Marco Vanoli]

Hi,
I am following a Tutorial to begin use Struts.
I have to make an automatic <logic:forward name="welcome"/> to a deep tree folder file.(/jsp/index.jsp)

Than i create an Global Forward :
<forward
name="welcome"
path="/jsp/index.jsp" />

So it works but the tutorial i follow make a different step. It crate an action forward
<action forward="/jsp/index.jsp" path="/default" />
and then the Global forward :
<forward name="welcome" path="/default.do" />

So what are the logic differences between the two aprroach?
Thankyou,
Bye Marco

PS: ON action forward,the attribute unknown="true" is only possible when i create a default action?