VLookup allows you to check to see if cell A exists in a range of cells.  This might be useful if you want to compare two lists of names, or DVD’s for example.

Just like the example pictured here:

(click on the picture to see all of it)

The formula used above is: =VLOOKUP(A6,DVDsIown!A:A,1,FALSE)

It’s simple once you get the hang of it.  You can download the Excel spreadsheet I used above, here.

References:
Microsoft Excel Online Help: VLookup reference
Tech on the net: Excel VLookup Function