excel compare columns for matches

1. Select the list in column A
2. Right-Click and select Name a Range...
3. Enter "ColumnToSearch"
4. Click cell C1
5. Enter this formula: =MATCH(B1,ColumnToSearch,0)
6. Drag the formula down for all items in B

If the formula fails to find a match, it will be marked #N/A, otherwise it will be a number.
If you'd like it to be TRUE for match and FALSE for no match, use this formula instead:
=IF(ISNA(MATCH(B1,ColumnToSearch,0)),FALSE,TRUE)