Comparing Application server file and internal table

hi all

Iam new to the world of ABAP. I have a requirement wherein i need to compare data in a internal table and that of the file. I need to extract the delta records( ie the record is found in the internal table but not in the file and vice versa ) and put it in another internal table. Which is the best way to do it?

Awaiting quick reply. Thanks

Nirmal.