extension service vs teaching

extension service and teaching both are nouns.

Word	Noun	Adjective	Verb	Adverb
extension service	Yes	No	No	No
teaching	Yes	No	No	No

As nouns, teaching is a hypernym of extension service; that is, teaching is a word with a broader meaning than extension service:

extension service: an educational opportunity provided by colleges and universities to people who are not enrolled as regular students
teaching: the activities of educating or instructing; activities that impart knowledge or skill

Other hypernyms of extension service include didactics, education, educational activity, instruction, pedagogy.

extension service (noun)	teaching (noun)
an educational opportunity provided by colleges and universities to people who are not enrolled as regular students	the profession of a teacher
	the activities of educating or instructing; activities that impart knowledge or skill
	a doctrine that is taught