insert vs plug in

insert is a noun but plug in is not a noun.

Word	Noun	Adjective	Verb	Adverb
insert	Yes	No	Yes	No
plug in	No	No	Yes	No

As verbs, plug in is a hyponym of insert; that is, plug in is a word with a more specific, narrower meaning than insert:

insert (noun)	plug in (noun)
(film) a still picture that is introduced and that interrupts the action of a film
(broadcasting) a local announcement inserted into a network program
an artifact that is inserted or is to be inserted
a folded section placed between the leaves of another publication

insert (verb)	plug in (verb)
place, fit, or thrust (something) into another thing	plug into an outlet
insert casually
put or introduce into something
fit snugly into