audiotape vs tape recording

audiotape and tape recording both are nouns.

Word	Noun	Adjective	Verb	Adverb
audiotape	Yes	No	No	No
tape recording	Yes	No	No	No

As nouns, tape recording is a hypernym of audiotape; that is, tape recording is a word with a broader meaning than audiotape:

Other hypernyms of audiotape include audio, audio recording, sound recording, tape, taping.

audiotape (noun)	tape recording (noun)
magnetic tape for use in recording sound	a recording made on magnetic tape
a tape recording of sound