Comparing data in two similar worksheets
 

I have to compare data in two reports to find the differences. The report
has approx 15 columns and 2500 rows, and I need to extract each entry that
has changed since the previous report. Each entry has an ID#, that may or
may not have been in both reports, or is in both reports but has differing
data in some of the columns. I am relatively new to using excel, so any help
at all is appreciated.