Stairway
Part of speech: noun
Definition: a set of steps allowing one to walk up or down comfortably.
Example sentence: Many fans were surprised when they learned that the little girl in drama 'Stairway To Heaven' was me.
Staircase
Part of speech: noun
Definition: a flight of stairs; a stairwaya connected set of flights of stairs; a stairwell
Example sentence: There was an incident, in 1912, which 'gave me a turn,' so to speak: when I brought the 'Nude Descending a Staircase' to the Independants, and they asked me to withdraw it before the opening.