Clarification on ME2A report

Hi,

Could you please explain what is the  business significance of ME2A report, I am the technical person and I know that it is used to display vendor confrimations.

for example we order a material  abc of quantity 100 and if the vendor confirms 10 quantity than that 10 quantity entry would be shown on ME2A output , if thats the case why its showing zero quantity also.

Thanks,

Balu