ECC System , what is th major difference - with a developer point of view?

If in an interview I am asked what are some differences I noticed in the ECC system and SAP 4.7, what should be the perfect answer for a ABAP developer?

I haven’t worked much in ECC system and noticed the changes with debugger.

Also if I have some report , forms or function module in SAP 4.7 ,can anyone tell me if I can copy them directly to a ECC system or do I have some particular steps or prerequisite to follow before that , if explained with example it will be helpful?

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Thanks,

Ameesha

Edited by: Alvaro Tejada Galindo on Feb 11, 2008 5:57 PM