insert vs append

insert is a noun but append is not a noun.

Word	Noun	Adjective	Verb	Adverb
insert	Yes	No	Yes	No
append	No	No	Yes	No

As verbs, append is a hypernym of insert; that is, append is a word with a broader meaning than insert:

Other hypernyms of insert include add, supply.

insert (noun)	append (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)	append (verb)
place, fit, or thrust (something) into another thing	state or say further
insert casually	fix to; attach
put or introduce into something	add to the very end
fit snugly into