subject field vs domain

subject field and domain both are nouns.

Word	Noun	Adjective	Verb	Adverb
subject field	Yes	No	No	No
domain	Yes	No	No	No

As nouns, domain is a hypernym of subject field; that is, domain is a word with a broader meaning than subject field:

Other hypernyms of subject field include knowledge base, knowledge domain.

subject field (noun)	domain (noun)
a branch 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