schoolwork vs lesson

schoolwork and lesson both are nouns.

Word	Noun	Adjective	Verb	Adverb
schoolwork	Yes	No	No	No
lesson	Yes	No	No	No

As nouns, lesson is a hyponym of schoolwork; that is, lesson is a word with a more specific, narrower meaning than schoolwork:

Other hyponyms of schoolwork include classroom project, classwork, prep, preparation.

schoolwork (noun)	lesson (noun)
work, such as schoolwork or piecework, that is done at home	a task assigned for individual study
	a unit of instruction
	punishment intended as a warning to others
	the significance of a story or event