Newbie sqlplus question

I'm a newbie to Oracle, so I don't know what to do here. I create 2-databases, ABC and XYZ. They are both local to the users. However, a single user has access to both of them (same user name). When they start a sqlplus session, how do they pick the database they want to use?

Thanks in advance
Joe Received on Sun Oct 20 1996 - 00:00:00 CEST