steps vs stairway

steps and stairway both are nouns.

Word	Noun	Adjective	Verb	Adverb
steps	Yes	No	No	No
stairway	Yes	No	No	No

As nouns, stairway is a hypernym of steps; that is, stairway is a word with a broader meaning than steps:

steps: a flight of stairs or a flight of steps
stairway: a way of access (upward and downward) consisting of a set of steps

Other hypernyms of steps include staircase.

steps (noun)	stairway (noun)
a flight of stairs or a flight of steps	a way of access (upward and downward) consisting of a set of steps
the course along which a person has walked or is walking in