In which category does personification belong? Is it a sound pattern, a literary device, a type of narrative, or a part of a narrative?
It is a literary device. See explanation.
A personification is a literary device. It means to give human fatures (or activities) to non human or abstract things.
The wind was gently whispering in the trees
This sentence gives a non human thing (i.e. wind) a purely human ability to speak (or whisper), so it is an example of personification.