I removed the following text from the Usage notes section:
Adverbs and prepositions are sometimes confused. To differentiate, adverbs typically describe how something was done; while prepositions often describe where something was done. For example:
"He threw the ball really fast." - Really and fast are both adverbs; really modifies fast and fast modifies (describes) threw.
"She spilled milk all over the place." - All over the place is a preposition, it describes where the milk went.