What are independent variables and automatic variables ? When they are used ?

These terms are not usually associated with Adabas. Where did you see them used? Please provide some context.

I have not used nor did I see it.But i want to know what it means ??

As Ralph noted, these are not terms that are associated with Adabas.

Natural does have AIVs , which are Application Independent Variables, but nothing just called Independent Variables.

Natural also has various options which are “automatic” but nothing close to automatic variables.

You said

How could you ask your original question if you have never tried to use nor seen these terms?

Do you have access to Natural/Adabas documentation?

By any chance are you attempting to pass an Adabas/Natural “test” to apply for a job?

There are “system variables” for Adabas files, which automatically generate user id and date/time values to attach to the Adabas record on create/update.