rungs
There is no word like lader. If you meant ladder, the steps of a ladder are called rungs.
rung
A ladder has different amount of steps, depending on how big it is.
A word ladder from "birds" to "raven" can be achieved with the following steps: "birds" → "bards" → "bared" → "bare" → "rave" → "raven." Each step changes one letter to form a new valid word.
The rungs of a ladder are the steps. Unless it is a step ladder, then they are just steps.
To create a word ladder from "face" to "lift" using only two spaces, you can go through the following steps: face lace lace → left left → lift So, the word ladder is: face → lace → left → lift.
18 steps
rungs
steps
11 rungs.
According to an ancient midrash (Tanchuma), as well as Jewish mysticism, Jacob's ladder (Genesis ch.28) had four steps. Bear in mind that it was a spiritual ladder and the steps were not close to each other.
The steps of a ladder are called rungs.