A staircase is a structure consisting of a set of steps leading from one floor to another. The newel is the main post at the beginning or end of a staircase, which supports the handrail and balusters. Balusters are the vertical posts that support the handrail of a staircase. A check is a type of stair tread that has a cut-out shape in the center. Together, these components form a staircase, which is an important architectural feature in many homes and buildings.