help desk vs helpdesk

help desk and helpdesk both are nouns.

Word	Noun	Adjective	Verb	Adverb
help desk	Yes	No	No	No
helpdesk	Yes	No	No	No

As nouns, help desk and helpdesk are synonyms defined as:

help desk and helpdesk: a service that provides information and assistance to the users of a computer network

help desk (noun)	helpdesk (noun)
a service that provides information and assistance to the users of a computer network	a service that provides information and assistance to the users of a computer network