What MATCH does
MATCH does not return the value you are looking for. It returns the position of that value inside a lookup range. That is why it is often used together with INDEX.
You can use MATCH on vertical lists, horizontal labels, and sorted breakpoint tables.
Practical examples
Find an exact position
=MATCH("Thu",$A$1:$G$1,0)
If "Thu" is the fifth item in the range, MATCH returns 5.
Use the result to drive another formula
=INDEX($B$2:$B$13,MATCH(E2,$A$2:$A$13,0))
This is the classic INDEX-MATCH combination for flexible lookups.
Common mistakes and notes
Confusing position with value
MATCH returns a number such as 5 or 11, not the matched text itself.
Approximate match rules matter
When match_type is 1 or omitted, the lookup array must be sorted ascending. When it is -1, the array must be sorted descending.
Wrong range shape
MATCH works against a single row or single column. If you point it at a two-dimensional table, the logic becomes harder to reason about and easier to break.