Storey is a concept in architecture and construction, meaning a single horizontal layer of the building placed between two adjacent ceiling panels. A storey covers all rooms and spaces located at the same level and separated from other floors by ceiling. Storeys are divided into above-ground and underground, and the most common types are ground floors, floors and cellars. The number of floors is one of the main parameters defining the size and characteristics of the building. A storey is also a unit of measurement used to determine the height of buildings.