To use the level, one simply places it on the surface or object to be checked. Then adjust the position until the bubble is centered. If the bubble is not in the center, it means that the surface or object is not level and needs to be adjusted to correct the alignment.
The spirit level is commonly used by craftsmen, construction workers and do-it-yourselfers to ensure that wall shelves, pictures, furniture, frames and other objects are properly aligned. It is a handy tool to make sure everything is level and has a professional appearance.