What is the difference between formal & informal system ( details please )??

You have to wear a tie in a formal system:D

With a matching shirt as well ;)

StuMegu and Curlyben: He posted in the Computer Network area and specifically he asked about Information Systems. So your answers are not appropriate.

In Information System, FORMAL means you hear it straight from the IT manager. On the other hand INFORMAL is when you hear rumors about the IT manager from peers.

Ok... ok... joking aside... I think by now you'd figured out that you have to be more specific in your question... otherwise it is tough to pass up these opportunities :)

Casey