OEM is similar to SQL Server Management Studio in that it gives you a look at the server information, error logs, scheduled tasks, and object information. OEM also provides some operating system information and performance statistics. OEM offers an easy view into a database and provides the ability to manage the database in a GUI.
NOTEManaging multiple databases in an enterprise environment is better left to the Grid Control, rather than the single instance of the Database Control. However, the Database Control for a single database is a good starting point for understanding the templates and setup for monitoring.