canvas vs oil painting

canvas and oil painting both are nouns.

Word	Noun	Adjective	Verb	Adverb
canvas	Yes	No	Yes	No
oil painting	Yes	No	No	No

As nouns, oil painting is a hypernym of canvas; that is, oil painting is a word with a broader meaning than canvas:

canvas (noun)	oil painting (noun)
a heavy, closely woven fabric	the art or method of painting with oil paints
the mat that forms the floor of the ring in which boxers or professional wrestlers compete	a picture painted with oil paints
a tent made of canvas fabric
a large piece of fabric (usually canvas fabric) by means of which wind is used to propel a sailing vessel
an oil painting on canvas fabric
the setting for a narrative or fictional or dramatic account

canvas (verb)	oil painting (verb)
cover with canvas