The illustration em_dbcontrol_dir_structure.gif consists of a diagram that shows a folder icon that represents the Oracle home directory created when you install an Oracle Database 10g database. Specifically, the illustrations shows the following directories inside the Oracle home:

- The `bin` directory, which contains the `emctl` and `emca` commands discussed later in this section

- The `sysman` directory, which contains the Enterprise Manager administration files

- The `hostname_sid` directory, which contains its own `sysman` directory. This `sysman` directory contains the Enterprise Manager configuration, logging, and administration files specific to the database identified in the `hostname_sid` directory name.

- The `oc4j` directory, which contains a j2ee directory, which contains the files required to deploy the Database Control application for each database instance you create in this Oracle home.