What is the difference between VLOOKUP, INDEX/MATCH and XLOOKUP?

VLOOKUP searches the leftmost column of a range and returns a value a fixed number of columns to the right. It can only look rightward, its column index is hard-coded so inserting a column breaks it, and it defaults to approximate match if you omit the last argument.

INDEX/MATCH separates finding the position from returning the value. It looks in any direction and survives column insertion. It works in every version of Excel.

XLOOKUP replaces both: exact match by default, any direction, a built-in not-found argument, and optional bottom-up search. It needs Microsoft 365 or Excel 2021.