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.
Many street lights are orange because of the type of bulb used. The two main types of street lighting used in the United States are sodium-vapor bulbs and mercury-vapor bulbs. Both types work by applying electricity to a sealed container of gas in order to create light.