Server Utilities :: Exporting Schema Using Consistent Parameter

I taking export using consistent parameter. Theoretically i can understand . practically i couldn't understand how it works.

for ex

I am updating tab1 table under sams user. table having one lakh records.
while updating the query using consistent=y and consistent=n. i mean

exp sams/sams file=cons.dmp owner=sams consistent=y
exp sams/sams file=cons2.dmp owner=sams consistent=n

then both files imported to separate user(sam ,san).
Updated info not visible in san and sam user.

I want to know practically how it works. I need perfect example. while using consistent=y and consistent=n