Impressionism vs art movement

Impressionism and art movement both are nouns.

Word	Noun	Adjective	Verb	Adverb
Impressionism	Yes	No	No	No
art movement	Yes	No	No	No

As nouns, art movement is a hypernym of Impressionism; that is, art movement is a word with a broader meaning than Impressionism:

Impressionism: a school of late 19th century French painters who pictured appearances by strokes of unmixed colors to give the impression of reflected light
art movement: a group of artists who agree on general principles

Other hypernyms of Impressionism include artistic movement.

Impressionism (noun)	art movement (noun)
a school of late 19th century French painters who pictured appearances by strokes of unmixed colors to give the impression of reflected light	a group of artists who agree on general principles