A preamble is usually used for formal documents; you wouldn't include one in a text to your best friend. noun-A preliminary statement, especially the introduction to a formal document that serves to explain its purpose. noun-An introductory occurrence or fact; a preliminary.
Halogen bulbs produce a bright white light. They become much, much hotter than other types of bulbs and should not be used near combustible materials or touched during or shortly after use. Fluorescent: These tube-shaped lights are often used as overhead lighting for large areas such as retail stores or home basements.
Types of Light Sources and Light Bulbs. The performance of any light fixture depends very much on the light source (bulb) used. Different bulbs produce different lighting effects, and many bulbs have widely varying performance. To save energy, select the most efficient light bulb that will provide the type of lighting you need. Beginning in mid-2011, the packaging on your favorite light bulbs will change.