This document provides information on various types of lamps used for illumination. It discusses fluorescent tubes, CFLs, mercury vapor lamps, sodium vapor lamps, and metal halide lamps. For each type of lamp, it describes the construction, working principle, advantages, disadvantages, and applications. The key information covered includes how the lamps produce light through gas discharge, their relative efficiencies and lifetimes, toxic materials used, and common uses for residential, commercial and industrial lighting.