door phone vs intercom

door phone and intercom both are nouns.

Word	Noun	Adjective	Verb	Adverb
door phone	Yes	No	No	No
intercom	Yes	No	No	No

As nouns, intercom is a hypernym of door phone; that is, intercom is a word with a broader meaning than door phone:

door phone: a set of electrical and electronic elements used to handle two-way communication (street to home) in houses, apartments or villas.
intercom: a communication system linking different rooms within a building or ship etc

Other hypernyms of door phone include intercommunication system.

door phone (noun)	intercom (noun)
a set of electrical and electronic elements used to handle two-way communication (street to home) in houses, apartments or villas.	a communication system linking different rooms within a building or ship etc