linking with data matches

[katk]

I would like to link two excel spreadsheets such that the information will match itself to a particular data point. That is, I want my inventory updates to link into my sales spreadsheet, but I also want to correlate the data so the item numbers match up. The way the spreadsheets are created, each monthly sales report only lists the items sold, so it might have only item numbers 101, 103, and 104 but not 102. Is there a way to link the inventory data into the sales sheets by item number such that item 101 on inventory will go to the row with 101 on sales, but 102 won't transfer at all? I hope I'm making sense.