refresher vs refresher course

refresher and refresher course both are nouns.

Word	Noun	Adjective	Verb	Adverb
refresher	Yes	No	No	No
refresher course	Yes	No	No	No

As nouns, refresher and refresher course are synonyms defined as:

refresher and refresher course: a course that reviews and updates a topic for those who have not kept abreast of developments

refresher (noun)	refresher course (noun)
a course that reviews and updates a topic for those who have not kept abreast of developments	a course that reviews and updates a topic for those who have not kept abreast of developments
a drink that refreshes
a fee (in addition to that marked on the brief) paid to counsel in a case that lasts more than one day