knowledge domain vs domain

knowledge domain and domain both are nouns.

Word	Noun	Adjective	Verb	Adverb
knowledge domain	Yes	No	No	No
domain	Yes	No	No	No

As nouns, knowledge domain and domain are synonyms defined as:

knowledge domain and domain: the content of a particular field of knowledge

Other synonyms of knowledge domain include knowledge base.

knowledge domain (noun)	domain (noun)
the content of a particular field of knowledge	the content of a particular field of knowledge
	people in general; especially a distinctive group of people with some shared interest
	(mathematics) the set of values of the independent variable for which a function is defined
	territory over which rule or control is exercised
	a particular environment or walk of life