Now that you know how vlookup works, here are other ideas on how to use it.
If you have to compare two files, let say January Sales report and January Collection report to get all unpaid January Sales or simply your Accounts Receivables.
Vlookup will do the trick, first you need to get the common fields for both files and one common field for these two files is the Invoice number. You then use the vlookup function on the January Sales report to look if these invoices are in the January Collection report, then we minus the result from the sales amount, tada! We now have your Accounts receivables from your January Sales. There is just another function you need to add in the VLOOKUP formula so it will not display #N/A, its the ISERROR formula. more about on the next post.