Leveling devices are tools used to determine whether a surface is horizontal (level) or vertical (plumb). Common types include the spirit level, which contains a liquid-filled tube with a bubble that indicates levelness, and the laser level, which projects a straight line of light to help align objects accurately. These devices are essential in construction, carpentry, and various DIY projects to ensure that structures, furniture, and installations are properly aligned. Using leveling devices helps prevent issues such as uneven floors or misaligned walls, contributing to the overall quality and safety of a project.