stair  | step

He climbedthe stairs/steps to his bedroom

There are 300 steps to the top of the mountain.

Please get me the bag upstairs.

Please get me some water downstairs.

staircase

amarble/stone/wooden staircase

ladder  

Heclimbed up the ladder to fix the roof.

t's on the sixth floor - let's takethe lift.

I went down in the lift.

escalator

/ˈeskəleɪtə(r)/

escalate  verb

The costhas escalated sharply.