Levelness
Levelness is the quality or condition of being level: lying horizontally or having a uniform height with no tilt. A level surface remains at the same height across its extent, in contrast to surfaces that slope or undulate. Levelness is a practical concern in construction, carpentry, and engineering, where accurate alignment affects function and appearance. It is related but not identical to plumbness, which concerns vertical alignment.
Common tools include the spirit level (bubble level), which indicates level when the bubble is centered; laser
Applications of levelness include building floors and countertops, cabinetry, masonry, roadbeds, and drainage systems, where correct
In mathematics, the term level commonly describes sets where a function has a constant value, known as