A newel is a post or pole that supports a spiral staircase or one end of a flight of stairs. When you put your hand on the banister of a stairway, you can see that the banister is held in place by a newel.
Newels are important structural elements of a stairway, providing the central support for a spiral staircase that winds around it, or holding up one end of a straight flight of stairs. Most newels are also decorative, with carved posts or fancy trim. Newel comes from the Old French word nouel, "knob or stone," from the Latin nodulus, the diminutive form of nodus, or "knot."