subdirectory vs directory

subdirectory and directory both are nouns.

Word	Noun	Adjective	Verb	Adverb
subdirectory	Yes	No	No	No
directory	Yes	No	No	No

As nouns, directory is a hypernym of subdirectory; that is, directory is a word with a broader meaning than subdirectory:

subdirectory: (computer science) a directory that is listed in another directory
directory: (computer science) a listing of the files stored in memory (usually on a hard disk)

subdirectory (noun)	directory (noun)
(computer science) a directory that is listed in another directory	an alphabetical list of names and addresses
	(computer science) a listing of the files stored in memory (usually on a hard disk)