Use Server Manager's DESCRIBE command to show the structure of a table.
A very useful Server Manager command is the DESCRIBE command.
DESCRIBE is usually used to view a list of columns in a database table or view.
The following example shows how it would be used to list the column definitions for the DBA_USERS view.

SVRMGR> DESCRIBE dba_users

The DBA_USERS view is a data dictionary view that returns information about the users who can log in to an Oracle database.

The DESCRIBE command can also be used to view function, procedure, and package headers.
The following command for example, would tell you about all the entry points in the UTL_FILE package, which is used to read and write files from within stored procedures.

SVRMGR> DESCRIBE utl_file

You can also retrieve information on a specific procedure or function in a package. Just name the procedure or function as a parameter to the DESCRIBE command.
A period is used to separate the specific procedure or function name from the package name, as shown in the following example:

SVRMGR> DESCRIBE utl_file.fflush

Go ahead and try these these commands yourself, using the simulation below.
Ora Describe Command

Now that you've seen a simulation of how the DESCRIBE command can work, those of you who are running Oracle8 on your machines should connect to your database using Server Manager, and try out this command for yourselves.