MongoDB: Difference between find and findOne methods in mongoDB ?

Answer 1

The basic difference between find() and findOne() is find() method can return multiple documents in search result while findOne() returns only the first document which matches selection criteria.

Answer 2

findOne():Returns one document that satisfies the specified query criteria. If multiple documents satisfy the query, this method returns the first document according to the natural order which reflects the order of documents on the disk.
syntax:

$query=array('name_filed'=>$name_any); // in php
    >db.collection.findOne($query);   //mongodb terminal

But In case of find(),
Returns all document which matches criteria or query;

 >db.collection_name.find($query);