explain() in Mongodb: differences between “nscanned” and “nscannedObjects”

Question

I cannot get the exact difference between \"nscanned\" and \"nscannedObjects\" in the Mongodb\'s explain query output.

On MongoDB Explain documentation I can read:

Answer 1

This means that :
The query returned 5 documents - n
scanned 9 documents from the index - nscanned
and then read 5 full documents from the collection - nscannedObjects

Similar example is given at :
http://docs.mongodb.org/manual/reference/method/cursor.explain/#cursor.explain

Answer 2

if "cursor" is Index ==> nscanned = no. of index scanned else if "cursor" is FullTableScan ==> nscanned = no. of document scanned

nscannedObjects ==> No. of document scanned

when querying, try to minimise all count, i.e. nscanned and nscannedObjects both are minimum means your query should run faster!