VLOOKUP

VLOOKUP (vertical lookup) is the function generations of analysts used to join data across tables. You give it a value to find, a range to search, the column number to return, and whether you want an exact or approximate match. It looks down the first column of the range and pulls the matching value from the column you named.

Its well-known limits are why XLOOKUP exists: VLOOKUP can only look to the right of the search column, breaks when columns are inserted (the return column is a fixed number), and defaults to approximate match, a frequent source of silent errors. For lookups in modern Excel, XLOOKUP or INDEX/MATCH are more robust. VLOOKUP is also a manual way to compare two lists, but for a full row-by-row diff a dedicated comparison is faster and less error-prone.