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.
What are they? The incandescent light bulb or lamp is a source of electric light that works by incandescence, which is the emission of light caused by heating the filament. They are made in an extremely wide range of sizes, wattages, and voltages. Incandescent bulbs are the original form of electric lighting and have been in use for over 100 years.