BAPI Examples

Hi ,

1.Can anyone please explain me what are the most commonly used BAPI across SD,FI,MM Modules

2. Please provide some sample code for the BAPI &explain me how to test BAPI

3.What are other diff between BAPI & FM ???

BAPI has clasess and methods

BAPI is remote enalbled - Any examples ??

Thanks,

Priya