A Bubble Level is an essential tool for achieving accurate horizontal or vertical leveling in various applications such as construction, carpentry, and DIY projects. It consists of a vial filled with liquid (usually alcohol or oil) and a small bubble. When the bubble is centered between marked lines within the vial, the surface is level. Bubble levels come in various sizes and designs, including handheld and bullseye levels, catering to different needs and preferences. They are indispensable for ensuring precision and alignment in both professional and household settings.