discipline vs field of study

discipline and field of study both are nouns.

Word	Noun	Adjective	Verb	Adverb
discipline	Yes	No	Yes	No
field of study	Yes	No	No	No

As nouns, discipline and field of study are synonyms defined as:

Other synonyms of discipline include bailiwick, field, study, subject, subject area, subject field.

discipline (noun)	field of study (noun)
training to improve strength or self-control	a branch of knowledge
the act of disciplining
the trait of being well behaved
a branch of knowledge
a system of rules of conduct or method of practice

discipline (verb)	field of study (verb)
punish in order to gain control or enforce obedience
develop (a child's or animal's) behavior by instruction and practice; especially to teach self-control