Oracle Security Question:

If a user wants to give some privileges to
another user or a group of users then they will create role
and they give this role to the users.let the privileges
be 'insert' and 'update' on 'emp' table then instead of
specifying them by their names they will create role which
inturn includes these methods. this role is further given
to the users.
If in futher if he wants to remove some
privilege given to the users, he can just alter the role
and remove that particular privilege such as he can remove
update from this created role..
Later the users cant do updations on that emp
table.but still can insert the values into that table.
Hence Roles are the easiest way to grant and
manage common privileges needed by different groups of
database users.Creating roles and assign each role to group
of users will simplify the job of assigning privileges to
individual users.