Description
The differences between the $ projection operator and $elemMatch projection operator could be better explained.
We do mention the array field limitation for $, but in the $elemMatch notes it just says "The $elemMatch projection operator is similar to the positional $ projection operator".
To further confuse things, the $elemMatch operator can be used in queries and the $ can be used in updates.
Perhaps we can do some sort of direct comparison table/summary?
Possible starting point: http://stackoverflow.com/questions/21519185/projection-vs-elemmatch