Audit table

Last week i have learned that Oracle gives you the chance of tracking changes of tables you want. Whenever a change
occurs for the columns you selected, it creates a record. It seems to be a very
useful feature. It is kind of technical staff though steps to implement are easy and
functional:
AuditTrail:Activate profile should be set to 'Yes'
system administrator>security>install enable audit for your oracle username
system administrator>security>groups create an audit group, define the tables in the group. (Custom tables should be registered to be listed here)
system administrator>security>tables columns, desired to trail, should be selected.
AuditTrail Update Tables concurrent should be run.
After the concurrent a new table should have been created, which has "_a" after the original table name.