A lava lamp is a decorative lighting device that contains a special liquid and wax. When the lamp is turned on, a light bulb at the base heats the wax, causing it to rise and fall in mesmerizing patterns. This movement creates a soothing visual effect, making lava lamps popular for home decor and relaxation. The design of a lava lamp typically features a glass container filled with colored liquid and a wax substance. The combination of heat and density differences between the wax and liquid allows the wax to form blobs that float and change shape, resembling flowing lava, hence the name lava lamp.